Intelligent quality-divided pressure-superposed non-negative pressure water supply control system and method

Abstract

The invention relates to the technical field of water supply control, and discloses an intelligent quality-based pressure-superposed non-negative pressure water supply control system and method, and the system comprises a data collection control module, a volume identification module, a water age observation module, a mixing decision module, and an impedance verification module. The effective volume parameters of the steady flow compensation tank are inversed through the pressure response characteristics of the variable frequency booster pump set in the starting stage; dynamically calculating the hydraulic retention time in the tank based on the system flow and the effective volume; when the residence time exceeds a safety threshold value, a forced mixing strategy is generated, and municipal inlet water is driven to be mixed with residence water by adjusting the opening degree of a bypass electric adjusting valve and controlling a pump set to operate; and meanwhile, verifying the effectiveness of the mechanical action of the valve according to the deviation between the real-time power and the theoretical reference power of the pump set after the regulation instruction is issued. Volume parameters can be corrected in real time, aged water is actively replaced under the low-flow working condition, closed-loop verification is carried out on faults of an executing mechanism, and the water supply quality and the system reliability are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of water supply control technology, specifically to an intelligent differential pressure superimposed pressure water supply control system and method. Background Technology

[0002] Pressure boosting systems are widely used in secondary pressurization water supply systems for high-rise buildings and urban communities. They buffer pressure fluctuations in the municipal water supply network and eliminate the effects of negative pressure through a flow stabilization tank. During low-flow periods at night or off-peak water usage times, to save energy, the system typically prioritizes municipal residual pressure and keeps the pumps in standby mode, resulting in the water in the flow stabilization tank remaining at a low flow rate or stagnant for extended periods. As the hydraulic retention time increases, residual chlorine in the water decreases, increasing the risk of microbial growth and severely impacting water quality.

[0003] Existing water quality assurance measures mostly employ timed cleaning or forced circulation mechanisms, whose control logic is typically based on the equipment's nominal volume or a fixed time setting. However, flow stabilization compensation tanks are mostly pneumatic structures, and their effective water storage volume exhibits dynamic characteristics, influenced by the pre-filled gas pressure of the air bladder, ambient temperature, and the degree of air bladder aging. Calculating the hydraulic retention time solely based on the static nominal volume leads to significant discrepancies between the calculated results and actual operating conditions, making it impossible to accurately determine the critical point of water aging, thereby resulting in energy waste or substandard water quality.

[0004] Furthermore, to address the issue of water retention, some systems attempt to adjust the opening of the bypass pipeline regulating valve to change the impedance, thereby forcibly driving the pump unit to extract water from the tank. However, as a mechanically moving component, the bypass regulating valve is prone to mechanical jamming, valve core detachment, or actuator failure during long-term operation. Existing control systems mostly rely on issuing commands or electrical feedback signals for control, making it difficult to directly verify whether the actual mechanical action of the valve is in place. If the valve fails to effectively throttle due to mechanical failure, the control system may misinterpret and execute a pressurization command, not only failing to achieve water replacement but also potentially causing fluctuations in the water supply pressure. Therefore, how to identify the effective volume in real time during operation and perform closed-loop verification of the mechanical effectiveness of the actuator is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an intelligent differential pressure superimposed pressure-free water supply control system and method, which solves the problems of inaccurate water age monitoring caused by dynamic changes in the effective volume of the flow stabilization compensation tank in existing pressure-free water supply systems, and the inability to verify the mechanical failure of the bypass regulating valve in real time, thus affecting the effectiveness of water quality control.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an intelligent pressure-fed, non-negative-pressure water supply control system, comprising: The module includes a data acquisition and control module, a volume identification module, a water age observation module, a blending decision module, and an impedance verification module. The data acquisition and control module is configured to collect pressure signals from the water supply network and operating data from the variable frequency booster pump set, calculate system flow data based on the pump characteristic model, and send control commands to the variable frequency booster pump set and the bypass electric regulating valve. As the sensing and execution center, it acquires municipal inlet water pressure signals, user outlet water pressure signals, motor speed signals, and active power signals through physical layer sensors, providing basic data support for subsequent algorithms.

[0007] The volume identification module is configured to receive the pressure signal and system flow data collected by the data acquisition and control module during the startup phase of the variable frequency booster pump set, and determine the effective volume parameters of the flow stabilization compensation tank based on the pressure response characteristics and flow relationship. The specific identification logic is based on the stiffness characteristics of the fluid system. During the transient process of pressure establishment during pump set startup, the correlation between the pressure rise rate and the average injection flow rate is used to inversely calculate the gas phase volume within the air bladder, thereby deriving the current effective liquid phase volume of the flow stabilization compensation tank. This can correct for volume parameter drift caused by changes in the pre-filled gas state of the air bladder, ensuring the basic accuracy of subsequent calculations.

[0008] The water age observation module is configured to dynamically calculate the hydraulic residence time in the steady-flow compensation tank using the system flow data and the effective volume parameters. Based on the law of conservation of mass, the module constructs a state observer, performing retention accumulation calculations when the system flow is extremely low and dilution and renewal calculations when flow passes through the tank, thereby quantitatively monitoring the aging degree of the water in the tank.

[0009] The mixing decision module is configured to generate a forced mixing control strategy when the hydraulic residence time reaches the water age safety threshold. The data acquisition and control module executes frequency and opening adjustment commands to drive the municipal influent and stagnant water to mix in proportion. By actively adjusting the opening of the bypass electric regulating valve to increase the hydraulic resistance of the bypass pipeline, the variable frequency booster pump set is forced to increase its speed to extract water from the flow stabilization compensation tank, thereby realizing the physical replacement and mixing of new and old water.

[0010] The impedance verification module is configured to verify the effectiveness of the mechanical action of the bypass electric regulating valve based on the real-time active power signal fed back after the opening adjustment command is issued, and to block the update of the hydraulic residence time value when the determination result is invalid. The impedance verification module utilizes the coupling relationship between the fluid pipeline impedance characteristics and the centrifugal pump shaft power to transform the action verification of the mechanical actuator into the verification of electrical parameters, preventing the false impression of water quality improvement caused by valve jamming.

[0011] Furthermore, the data acquisition and control module internally stores a head-flow characteristic curve model of the variable frequency booster pump set at rated speed; the data acquisition and control module uses the centrifugal pump similarity law to establish a nonlinear equation describing the mapping relationship between the actual head, motor speed and system flow rate at non-rated speed, and solves the system flow rate data through analytical equations, realizing soft flow measurement under flow meter-less conditions.

[0012] Furthermore, the volume identification module locks the start-up transient window of the variable frequency booster pump set from a zero-flow dormant state to the establishment of constant pressure, extracts the rate of change of the user's outlet water pressure signal over time and the average injection flow rate within the start-up transient window; constructs a fluid stiffness model based on the gas polytropic process equation, calculates the instantaneous gas volume of the airbag, and determines the effective volume parameters by combining it with the nominal total volume of the flow stabilization compensation tank. In addition, the volume identification module is also equipped with exponentially weighted moving average filtering logic to smoothly update the effective volume parameters and deduct the structural dead zone volume to ensure that the parameters only represent the volume of active water participating in the flow.

[0013] Furthermore, the water age observation module switches between a stagnation accumulation mode and a flow dilution mode based on the magnitude of the system flow data. When the flow rate is less than the micro-flow threshold, it is determined to be a stagnation condition, and the hydraulic residence time increases linearly. When the flow rate is greater than the threshold, it is determined to be a flow condition, and a dilution term is calculated based on the ratio of flow rate to effective volume, causing the hydraulic residence time to decrease exponentially.

[0014] Furthermore, when generating the strategy, the mixing decision module calculates the target opening command using the inverse function of the valve flow characteristic function, and simultaneously calculates the feedforward speed command to compensate for pressure drop. When the hydraulic residence time value decreases to a reset threshold below the safety threshold, the forced mixing strategy is revoked, and the system returns to the energy efficiency priority control mode.

[0015] Furthermore, the impedance verification module pre-stores a theoretical reference power model, which characterizes the functional relationship between shaft power and rotational speed of the bypass electric regulating valve at a specific throttling opening. The impedance verification module determines whether the valve has experienced a mechanical fault by comparing the deviation between the theoretical reference power and the real-time active power. A method for controlling intelligent pressure-fed, non-negative-pressure water supply includes the following steps: At the moment the water supply system is started, the pressure change rate and the instantaneous flow rate are collected, and the current effective volume parameters of the flow stabilization compensation tank are calculated using the fluid stiffness model. Real-time monitoring of system flow data, combined with the effective volume parameters, is used to perform an integral calculation on the hydraulic residence time value in the flow stabilization compensation tank; Determine whether the hydraulic residence time value has reached the preset water age safety threshold; if it has, generate a forced mixing control strategy, output an opening adjustment command to control the bypass electric regulating valve to throttle, and drive the water pump to run to implement proportional mixing; After outputting the opening adjustment command, the deviation between the actual power and the theoretical reference power of the variable frequency booster pump set is calculated. The mechanical action of the bypass electric regulating valve is determined based on the deviation value; if it is invalid, the update of the hydraulic residence time value is blocked and an alarm is triggered.

[0016] This invention provides an intelligent differential pressure superimposed pressure water supply control system and method. It has the following beneficial effects: 1. This invention uses a volume identification module to calculate the effective volume parameters of the flow stabilization compensation tank during the pressure establishment process of the variable frequency booster pump set, utilizing the pressure change rate and average injection flow rate. This allows for real-time correction of volume parameter deviations caused by changes in the pre-filled gas pressure of the airbag or airbag aging, ensuring that the water age observation module can perform integral calculations based on the actual water storage volume. This improves the accuracy of hydraulic retention time calculations and avoids distorted water quality judgments due to incorrect volume estimation.

[0017] 2. This invention, through the cooperation of a mixing decision module and a data acquisition and control module, actively reduces the opening of the bypass electric regulating valve to increase pipeline impedance when the hydraulic residence time exceeds a safety threshold, while simultaneously controlling the operation of the variable frequency booster pump set. This control strategy can force the municipal influent and the stabilizing compensation tank to mix and replace in proportion under low flow or low flow conditions at night. This solves the problem that traditional negative pressure-free water supply equipment can only passively wait for users to use water to refresh the water in the tank during low water usage periods, thus ensuring the quality of the supplied water.

[0018] 3. This invention utilizes an impedance verification module to monitor the active power signal after executing the opening adjustment command. By calculating the deviation between the actual power and the theoretical reference power, the effectiveness of the mechanical action of the bypass electric regulating valve is determined. By utilizing the sensitivity of the centrifugal pump shaft power to changes in pipeline impedance, indirect verification of valve mechanical faults or jamming is achieved. When the determination is invalid, the water age update logic is locked to prevent the system from misjudging that the water quality has been improved due to actuator failure, thereby improving the reliability of the control system. Attached Figure Description

[0019] Figure 1 This is a system framework diagram of the present invention; Figure 2 This is a schematic diagram of the method flow of the present invention; Figure 3 This is a schematic diagram of the operation logic of the data acquisition and control module of the present invention; Figure 4This is a schematic diagram of the effective volume inversion logic of the present invention; Figure 5 This is a schematic diagram of the water age discretization integral logic of the present invention; Figure 6 This is a schematic diagram of the mixing decision state transition logic of the present invention; Figure 7 This is a schematic diagram of the impedance verification logic based on power fingerprinting of the present invention; Figure 8 This is a comparison chart of water age change curves under the same control strategy of the present invention; Figure 9 This is a pressure stability analysis diagram of the forced blending process of the present invention; Figure 10 This is a schematic diagram of the device structure of the present invention.

[0020] The components include: 1. Municipal water inlet network; 2. User-side water outlet network; 3. Pressure sensor; 4. Bypass pipeline; 5. Bypass electric regulating valve; 6. Flow stabilization compensation tank; 7. Variable frequency booster pump set; 100. Data acquisition and control module; 200. Volume identification module; 300. Water age observation module; 400. Mixing decision module; 500. Impedance verification module. Detailed Implementation

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

[0022] Please see the appendix Figure 1 and attached Figure 10 This invention provides an intelligent pressure-fed, non-negative-pressure water supply control system, comprising: The system includes a data acquisition and control module 100, a volume identification module 200, a water age observation module 300, a blending decision module 400, and an impedance verification module 500.

[0023] The data acquisition and control module 100 is electrically connected to the sensor and actuator drive unit in the water supply network through the signal acquisition interface. It is configured to acquire basic operating data of the physical layer in real time. The basic operating data includes the municipal water inlet pressure signal and the user water outlet pressure signal from the pressure sensor 3, as well as the motor speed signal, torque signal and active power signal from the variable frequency drive. The data acquisition and control module 100 internally stores the head-flow characteristic curve model of the variable frequency booster pump group 7. It is configured to calculate and output the system flow data based on the real-time acquired motor speed signal and user water outlet pressure signal. It is also configured with a control output port for sending frequency commands to the variable frequency drive and opening adjustment commands to the bypass electric regulating valve 5. The volume identification module 200 is communicatively connected to the data acquisition and control module 100. It is configured to perform calculations during the startup process of the variable frequency booster pump group 7 switching from the dormant state to the running state. It receives the user outlet water pressure signal, motor speed signal and system flow data during the startup process. Based on the correlation model between the fluid bulk elastic modulus and the pressure change rate, it calculates the current effective volume parameters of the flow stabilization compensation tank 6. The effective volume parameters reflect the influence of the pre-filled gas state of the air bladder in the flow stabilization compensation tank 6 on the water storage volume. The mixing decision module 400 is communicatively connected to the water age observation module 300. The mixing decision module 400 is configured to receive the hydraulic residence time value calculated in real time and compare the hydraulic residence time value with the preset water age safety threshold. When the hydraulic residence time value is less than the water age safety threshold, an energy efficiency priority control strategy is generated; when the hydraulic residence time value is greater than or equal to the water age safety threshold, a forced mixing control strategy is generated. The forced mixing control strategy includes specific opening adjustment commands and frequency commands issued by the data acquisition control module 100 to drive the municipal water intake and the stabilizing compensation tank 6 to mix in proportion. Impedance verification module 500 is connected to blending decision module 400 and data acquisition and control module 100 respectively. It is configured to monitor the system response of bypass electric regulating valve 5 after receiving the opening adjustment command issued by blending decision module 400. Impedance verification module 500 obtains the active power signal of variable frequency booster pump group 7 through data acquisition and control module 100, calculates the deviation between actual power and theoretical reference power, determines whether the mechanical action of bypass electric regulating valve 5 is effective based on the power deviation, and feeds back the determination result to water age observation module 300. When the determination result is invalid, water age observation module 300 stops diluting and updating the hydraulic residence time value in response to the determination result, realizing closed-loop interlock of control logic. See attached document Figure 2 , Figure 2 This is a flowchart of an intelligent differentiated pressure superimposed pressure water supply control method according to an embodiment of the present invention. The present invention provides an intelligent differentiated pressure superimposed pressure water supply control method, comprising the following steps: S10, at the instant the water supply system starts from the dormant state, collects the rate of change of the user's outlet water pressure signal over time and the instantaneous flow rate at startup, and uses the fluid volume elastic modulus model to calculate the current effective volume parameters of the steady flow compensation tank 6. S20, real-time monitoring of system flow data, combined with the calculated effective volume parameters, and integral calculation of the hydraulic residence time value in the steady flow compensation tank 6 based on the law of conservation of mass; S30, determine whether the real-time calculated hydraulic retention time value has reached the preset water age safety threshold; if it has not reached, maintain the conventional energy efficiency priority control strategy; if it has reached or exceeded the threshold, generate a forced mixing control strategy, output an opening adjustment command to control the bypass electric regulating valve 5 to open, and output a frequency command to adjust the water pump speed, and implement the ratio mixing of municipal water intake and tank stagnant water. S40, after outputting the opening adjustment command, collects the real-time active power signal of the variable frequency booster pump group 7 and calculates the deviation between its actual power and the theoretical reference power. S50: Determine whether the mechanical opening action of the bypass electric regulating valve 5 is effective based on the deviation value; if the action is effective, allow the hydraulic residence time value to be updated to reflect the improvement in water quality; if the action is ineffective, block the dilution update of the hydraulic residence time value and trigger a fault alarm.

[0024] See attached document Figure 3 The data acquisition and control module 100, serving as the system's underlying sensing and command interaction hub, physically includes a multi-channel analog input / output unit, a digital logic control unit, and a fieldbus communication unit. In this embodiment, the data acquisition and control module 100 establishes an electrical connection via shielded twisted-pair cables with the inlet pressure sensor 3 installed at the municipal water inlet network 1 and the outlet pressure sensor 3 installed at the user-side outlet network 2. The inlet and outlet pressure sensors 3 are configured to convert the detected fluid pressure physical quantity into a 4-20mA standard current signal or a 0-10V voltage signal and transmit it to the analog input port of the data acquisition and control module 100. The data acquisition and control module 100 internally includes an analog-to-digital converter unit that discretizes the analog electrical signal at a preset sampling frequency to generate a digitized municipal water inlet pressure signal. and user water pressure signal .

[0025] To obtain the operating status of electromechanical equipment, the data acquisition and control module 100 establishes a bidirectional digital communication connection with the frequency converter drive via an industrial fieldbus protocol. The communication connection is configured to read operating status data from the internal registers of the frequency converter drive in real time, including motor speed signals. Output torque signal and active power signal To ensure the time synchronization of subsequent algorithms, the data acquisition and control module 100 synchronously latches pressure data from pressure sensor 3 and motor operation data from the frequency converter driver within the same control cycle, constructing a timestamp data frame containing the system state at the same moment. Simultaneously, for the control of the bypass electric regulating valve 5, the data acquisition and control module 100 is equipped with an analog output port, outputting a 4-20mA control current or a PWM pulse width modulation signal with adjustable duty cycle as the opening adjustment command. This drives the actuator of the electric regulating valve to operate.

[0026] Specifically, the data acquisition and control module 100's memory pre-loads the variable frequency booster pump 7 at its rated speed. The head-flow characteristic curve data is derived from performance samples provided by the pump manufacturer or field measurement data during system commissioning. It is fitted to a second-order polynomial using the least squares method, characterizing the pump's head at rated speed. With traffic The inherent mapping relationship.

[0027] During system operation, the flow soft measurement logic unit first uses the real-time collected user outlet water pressure signal. With municipal water inlet pressure signal Calculate the current actual head of the variable frequency booster pump set 7. The actual head This represents the boost pressure applied to the fluid by the pump unit, and the calculation logic is as follows: ; in, This is a pipeline hydraulic loss correction item. The pipeline hydraulic loss correction item is pre-calculated and set based on the pipeline length, pipe diameter and friction coefficient in the pump house, or it is calibrated based on the pressure difference between the inlet and outlet during system commissioning.

[0028] The flow rate soft measurement logic unit, based on the similarity law of centrifugal pumps, determines the current non-rated speed. Mapping the actual operating point to the rated speed The equivalent operating point is determined. According to the similarity law, the head is proportional to the square of the rotational speed, and the flow rate is proportional to the first power of the rotational speed. Based on this physical constraint, a description of the instantaneous flow rate of the current system is established. Nonlinear equations: ; In the formula, This indicates the system head under the current actual operating conditions. This indicates the real-time speed of the motor. Indicates the rated speed of the motor. The scaling factor representing the similarity law of head variation with the square of rotational speed. Indicates instantaneous flow rate. This represents the flow rate equivalently mapped to the rated speed. This represents the coefficient of the quadratic term of the head-flow characteristic. This represents the coefficient of the first term of the head-flow characteristic. Represents the head-flow characteristic constant term, where It is usually a negative value, which indicates that the head decreases as the flow rate increases.

[0029] The above equation, after simplification, becomes a function relating to the system's instantaneous flow rate. The flow rate soft measurement logic unit uses the quadratic equation to analytically calculate the instantaneous flow rate of the system. The numerical solution is obtained. During the calculation process, the logic unit first calculates the discriminant of the quadratic equation. If the discriminant Then solve the equation and take the positive real roots as the calculation result; if the discriminant is affected by sensor noise... Then the system instantaneous flow Set it to the calculated value from the previous time step or zero to prevent the algorithm from crashing. The final output is... The calculation is processed by moving average filtering to eliminate abrupt changes in calculation caused by pressure fluctuations or signal noise, and the calculation results are limited to 0 to the maximum allowable flow rate of the water pump. Within the specified range, it is available for subsequent modules to call.

[0030] See attached document Figure 4 In this embodiment, the volume identification module 200 serves as the core parameter calibration unit to ensure the accuracy of subsequent water age observations. Its operating logic is based on the transient pressure response principle in gas-liquid two-phase fluid dynamics. The volume identification module 200 maintains real-time communication with the data acquisition and control module 100 and is configured to invert the current true effective volume of the steady flow compensation tank 6 by utilizing the dynamic characteristics during the system pressure establishment process at the moment the variable frequency booster pump group 7 switches from a dormant state to an operating state.

[0031] In this embodiment, the triggering time for effective volume identification is defined as the transient time window from the zero-flow sleep state to the pump starting and establishing pressure. Specifically, when the data acquisition and control module 100 detects the user's outlet water pressure... When the wake-up pressure is below the set threshold and a start command is sent to the inverter drive, a start sampling window is locked. Sampling window It begins when the inverter's output frequency is greater than zero and ends when the user's outlet water pressure is equal to the specified value. The moment when 95% of the preset target constant pressure is first reached. Within this window, since the check valve at the end of the pipeline or the user's tap is not fully opened, it can be regarded as an approximately closed elastic container, and the rate of pressure rise inside it mainly depends on the flow rate of the injected fluid and the compressibility characteristics of the pre-charged gas in the container.

[0032] This embodiment employs a physical identification model based on the gas state equation. In the steady-flow compensation tank 6, the compressibility of water is much less than that of gas; therefore, the total elastic modulus is dominated by the gas state within the air bladder. This is based on the gas polytropic process equation. (in For absolute pressure, For gas volume, (This is a polytropic index), and the rate of pressure change is inversely proportional to the gas volume. Based on this principle, this invention constructs a mathematical correlation model that inversely calculates the gas volume by the slope of pressure rise, thereby deriving the effective volume of the water body.

[0033] The specific parameter calculation logic is as follows: First, the system calculates the parameters during the initial sampling window. The pressure change rate and average injection flow rate are used to inversely calculate the instantaneous gas volume inside the airbag at the current moment using the fluid stiffness formula. : ; In the formula, This represents the estimated instantaneous volume of gas inside the airbag. Indices representing polytropic gas processes. This indicates the average absolute pressure within the initial sampling window. This indicates the average injection flow rate within the initial sampling window, which is obtained by the data acquisition and control module 100 based on the average motor speed and average pressure using the aforementioned soft flow measurement algorithm. This indicates export pressure. This represents the average slope of the user's outlet water pressure over time within the initial sampling window, obtained by linear fitting of the pressure sampling points using the least squares method. The subscript indicates the average value, and the subscript indicates that it was obtained through least-squares linear fitting. To represent the differential, Time variable.

[0034] Subsequently, based on the physical structural conservation of the flow stabilization compensation tank 6, the effective water volume parameters for subsequent water age observation were calculated. Effective water volume parameters The formula for calculating the actual amount of water stored in the tank under the current pressure is as follows: ; In the formula, This is the instantaneous value of the effective water volume calculated for a single activation event. The nominal total volume of the flow stabilization compensation tank 6 is an inherent property of the equipment. The dead zone volume of the tank refers to the residual water or structural dead zone that cannot be discharged when the tank is emptied. It is typically taken as... 1% to 3%.

[0035] Due to pressure pulsation, water hammer effect, and electronic noise inherent in the sensor itself in industrial environments, the results of a single calculation are limited. Random errors may exist. To ensure the stability of the control parameters, an exponentially weighted moving average filtering algorithm is used to smooth the calculation results, thereby updating the final effective volume parameters. The update strategy follows the iterative formula below: ; In the formula, For the current number The updated effective volume parameters of the flow stabilization compensation tank 6 after the second startup event will be transmitted to the water age observation module 300 for subsequent calculations. On the first startup, This represents the instantaneous estimate of the effective volume calculated in the current startup event. The valid volume parameters stored since the last startup event update. This is a smoothing factor, with a value ranging from 0.05 to 0.15. Indicates the first The valid volume parameters stored after the next startup event are updated.

[0036] Using the above method, the volume identification module 200 can automatically track the reduction in gas volume caused by minor gas leakage from the air bladder inside the flow stabilization compensation tank 6 (i.e., system hardening). Increase, calculated It becomes smaller, thus making the calculated The system adjusts parameters in real time to detect phenomena such as increased water volume, ensuring the water age calculation model is always based on actual physical conditions. The initial volume parameters of the flow stabilization compensation tank 6 can be manually entered from the nameplate data or calibrated once during the controller initialization phase. The initial value of .

[0037] See attached document Figure 5 In this embodiment, the water age observation module 300 uses mathematical modeling to quantitatively monitor the water retention time in the flow stabilization compensation tank 6. The water age observation module 300 is communicatively connected to the volume identification module 200 and the data acquisition and control module 100. In this embodiment, the flow stabilization compensation tank 6 adopts a fluid-through structure, meaning that municipal water must flow through the inner cavity of the flow stabilization compensation tank 6 before being pumped by the variable frequency booster pump set 7.

[0038] At the principle level, hydraulic residence time is considered a passive scalar quantity in a fluid. Based on the principles of mass conservation and transport, the average rate of change of water age within the control volume depends on the algebraic sum of the natural time rate of increase and the fluid displacement rate. The water age observation module 300 constructs a state equation based on this principle and periodically performs discretized integral operations to adapt to the controller's digital scan cycle.

[0039] Specifically, the water age observation module 300 reads the real-time system flow data output by the data acquisition and control module 100 in each control cycle. And the volume identification module 200 updates the effective volume parameters. Based on system traffic data The algorithm logically switches between the stagnation accumulation mode and the flow dilution mode based on the numerical value.

[0040] When system traffic data When the flow rate is less than the preset micro-flow threshold, the flow stabilization compensation tank 6 is determined to be in a stagnant state. In this embodiment, it is configured to be 0.5% to 2.0% of the rated flow rate of the variable frequency booster pump set 7 (for example, for a rated flow rate of 10m³ / h). 3 For pump sets operating at / h, the threshold is set to 0.05m. 3 / h to 0.2m 3 / h), or the minimum non-zero flow rate threshold that can be effectively identified by the flow rate soft measurement algorithm. This threshold is set to shield flow calculation errors caused by pressure sensor zero-point drift, electronic signal noise, or minor physical leaks in the pipeline, ensuring that the system only triggers water age dilution update calculations when substantial effective water use occurs. Municipal water intake is suspended from entering the tank, and the water inside the tank is approximately in a closed storage state, with mixing effects ceasing. The water age observation module 300 performs retention accumulation calculations; at this time, the water age increases linearly with time, and its discretization formula is: ; In the formula, For the current control cycle The hydraulic residence time value calculated at each moment. For the previous control cycle The hydraulic residence time value stored at all times. In this embodiment, the sampling period or calculation step size of the control system is used. It should be consistent with the program scan cycle of the PLC, and is usually set to 10ms to 100ms.

[0041] When system traffic data When the flow rate exceeds the micro-flow threshold, the system determines that the steady-flow compensation tank 6 is in a flowing condition. At this time, fresh water from the municipal pipe network continuously flows into the tank, mixes with the stagnant water inside, and is then pumped out. The water age observation module 300 performs a flow dilution calculation based on mass balance, and its discretized iterative formula is as follows: ; In the formula, Indicates the first Water age estimates at discrete time points Indicates the current discrete computation step number. This represents the water age estimate from the previous calculation step. Indicates the first The system traffic was measured at a specific time. Indicates the time step of discrete computation. This indicates the effective water volume of the current flow stabilization compensation tank 6.

[0042] With traffic Increase or effective volume The decrease in the value of the dilution term increases its weight, making it... The numerical value decreases exponentially and approaches the theoretical average dwell time. .

[0043] To ensure the convergence of numerical calculations and the rationality of their physical meaning, the water age observation module 300 integrates boundary condition processing logic. First, to meet numerical stability requirements, the calculation step size... The Courant number constraint must be satisfied, i.e. If this condition is not met under extremely high flow rate and small volume conditions, the step size will be automatically segmented and refined for calculation. Secondly, if the calculation result is negative due to signal noise, it will be forcibly clamped to zero. Simultaneously, the module has a saturation upper limit; when the calculation result exceeds this limit, it will stop accumulating and set a long-term stagnation alarm. For the initial conditions after the system's first power-on or reset, the water age observation module 300 will... Initialize to a preset safe and conservative value or read the value recorded in the non-volatile memory from the previous power failure to prevent misjudgment during the cold start phase.

[0044] See attached document Figure 6 In this embodiment, the blending decision module 400 is configured to resolve the control trade-off between water supply energy efficiency and water quality safety. It is communicatively connected to the water age observation module 300 and the data acquisition and control module 100. The blending decision module 400 has built-in finite state machine-based operating logic, defining two mutually exclusive operating states: an energy efficiency priority mode and a forced blending mode, and using water age observation values... As a trigger variable for state transition.

[0045] In this embodiment, the physical topology of the water supply system includes a municipal direct supply bypass pipeline 4 and a booster pipeline connected in series with a flow stabilization compensation tank 6, both located between the municipal water inlet and the user's water outlet. An electric regulating valve is installed on the bypass pipeline 4 to regulate the flow rate ratio through the bypass pipeline 4.

[0046] During initialization and normal operation, the mixing decision module 400 defaults to energy efficiency priority mode. In energy efficiency priority mode, the system control strategy prioritizes reducing power consumption. When the municipal water inlet pressure... Meet user-defined pressure At this time, the electric regulating valve is fully opened, utilizing the residual pressure of the municipal water supply network to directly supply water to users, while the variable frequency booster pump set 7 enters a dormant shutdown state. During this period, the water in the flow stabilization compensation tank 6 remains stagnant. The mixing decision module 400 reads the hydraulic residence time output by the water age observation module 300 in real time. and compare it with the preset water age safety threshold. A comparison is made. In this embodiment, the water age safety threshold is... Based on local temperature and water quality standards, the preferred range is 12 to 24 hours.

[0047] When detected If this indicates a risk of water aging in the tank, the mixing decision module 400 immediately switches to forced mixing mode. The control objective of forced mixing mode is to forcibly change the fluid flow direction of the pipeline network without causing pressure fluctuations at the user end, forcing some municipal water intake to flow through the flow stabilization compensation tank 6 to replace the stabilizing water.

[0048] In forced mixing mode, the mixing decision module 400 executes a combined control strategy of bypass throttling and pump pressurization. Specifically, since the municipal direct supply path has the lowest flow resistance, the water flow will not pass through the flow stabilization compensation tank 6 without intervention. Therefore, the module first calculates a target opening degree for a partially open electric regulating valve. The hydraulic resistance of the bypass pipe 4 is artificially increased, making it impossible for the bypass flow rate to fully meet the user's needs. The resulting pressure drop will trigger the start of the variable frequency booster pump 7, which will then draw water from the flow stabilization compensation tank 6 for pressurization and replenishment, thereby physically achieving the mixing of municipal direct water supply (via the bypass pipe) and stagnant water in the tank (via the pump pipe) at the user end.

[0049] To quantify and control the mixing process, this embodiment defines a mixing ratio coefficient. This represents the flow rate passing through the flow stabilization compensation tank 6 (i.e., the water pump) per unit time. Total system traffic The proportion of [something]. The mixing decision module 400, based on the current total system flow demand, uses the valve flow characteristic equation to inversely calculate the opening command of the target electric regulating valve. : ; In the formula, This indicates the control signal for the opening degree of the electric regulating valve. This represents the inverse function of the valve's flow characteristic function, used to deduce the valve opening from the target flow rate. Indicates the mixing ratio coefficient. This indicates the current total system traffic demand. Indicates the inlet water pressure of the municipal water supply network. This indicates the target pressure on the user side.

[0050] At the same time, in order to compensate for the change in valve opening To reduce the instantaneous pressure fluctuations on the user side, the mixing decision module 400 sends the calculated feedforward speed command to the frequency converter driver, driving the water pump to output flow. This ensures that the total traffic after synthesis is balanced with user demand.

[0051] The logic for exiting the blending mode employs a hysteresis comparison mechanism. The blending decision module 400 continuously monitors the gradually decreasing hydraulic residence time as the replacement process proceeds. Only when Reduced to the preset reset threshold Only then does the module determine that the water quality update is complete, immediately canceling the forced mixing command, restoring the electric regulating valve to the fully open state, stopping the water pump, and returning to the energy efficiency priority mode. In this embodiment, the reset threshold... Setting the time to 1 to 2 hours is significantly lower than the safe water age threshold. This is to prevent the system from frequently starting and stopping and oscillating at the critical point.

[0052] See attached document Figure 7 In this embodiment, the impedance verification module 500 is configured to perform actuator fault diagnosis based on electrical parameter characteristics, and it is communicatively connected to the mixing decision module 400 and the data acquisition and control module 100. The operating logic of the impedance verification module 500 is based on the inherent physical coupling relationship between the impedance characteristics of the fluid pipeline network and the shaft power of the centrifugal pump. For the centrifugal water pump used in this embodiment, its shaft power... With transport flow It exhibits a positive correlation characteristic. When the bypass electric regulating valve 5 performs a throttling action, i.e., the opening degree... When the flow rate decreases, the local hydraulic loss coefficient of the bypass branch increases, leading to an increase in the overall fluid resistance of the entire pipeline system. Assuming a constant pump speed, this increased resistance forces the pump's operating point to shift to the upper left along its head-flow characteristic curve, resulting in a decrease in output flow and consequently a drop in pump shaft power. Conversely, if the valve is fully open, the pipeline resistance is at its minimum, the pump flow is at its maximum, and the shaft power reaches its peak.

[0053] To achieve quantitative verification, the impedance verification module 500 stores a theoretical reference power model in its memory. This theoretical reference power model is a third-order polynomial obtained during system debugging by controlling the bypass electric regulating valve 5 to a preset benchmark verification position and controlling the water pump to perform multi-point frequency conversion sweeping, collecting a set of benchmark data on speed and power, and fitting it using the least squares method. During system operation, when the mixing decision module 400 issues forced mixing commands and valve adjustment commands, the impedance verification module 500 uses the currently collected real-time motor speed... The theoretical reference power under the expected valve condition is calculated using a reference model. The calculation formula is as follows: ; In the formula, Indicates the theoretical reference power. Represents the fitting coefficients of the third-order terms. This represents the normalized ratio of rotational speed. This indicates the real-time motor speed. Indicates the rated speed of the motor. This represents the cube term of the normalized rotational speed. The coefficients represent the second-order fitting coefficients, obtained from regression of historical data. This represents the quadratic term of the normalized rotational speed. The coefficients represent the first-order fitting coefficients, obtained from regression of historical data. This represents the first-order term of the normalized rotational speed.

[0054] After obtaining the theoretical reference power, the impedance verification module 500 reads the real-time active power fed back by the frequency converter driver. And calculate the absolute value of the power residual. The residual characterizes the degree of deviation between the actual hydraulic impedance of the pipe network and the theoretical model. The calculation and judgment logic is as follows: ; ; This represents the absolute value of the power residual, used to characterize the deviation between actual operating conditions and the theoretical model. This represents the real-time active power, obtained from feedback from the frequency converter drive. This represents the theoretical reference power, calculated from the reference power model. Represents state variables, This indicates the status determination result of the valve actuator. Indicates a normal state. Indicates an abnormal / fault status. This indicates the power deviation verification threshold.

[0055] The value range is set to 5% to 10% of the motor's rated power. This threshold setting takes into account the power measurement error caused by grid voltage fluctuations and the drift of the pump's mechanical efficiency with operating time.

[0056] If calculated Exceeding the threshold indicates that the actual pipeline impedance does not match the expected impedance. Specifically, when the system commands the valve to close slightly to force mixing, the theoretical power... The pressure should be at a lower level; if the valve is still fully open due to mechanical jamming, the actual pipeline resistance is lower, resulting in an increase in the actual flow rate of the pump at the same speed, thus increasing the real-time active power. Significantly higher than the theoretical reference power This triggers a fault determination.

[0057] The judgment result of the impedance verification module 500 is logically interlocked with that of the water age observation module 300. Once the judgment result is... The impedance verification module 500 immediately triggers the safety interlock mechanism: First, it sets the actuator fault alarm flag and prompts for maintenance through the human-machine interface; second, it sends a freeze command to the water age observation module 300 to forcibly stop the water age monitoring. The updated calculation may be marked as unreliable. This is because when the valve fails to operate, the actual proportion of the flow passing through the flow stabilization compensation tank 6 is... The results will deviate significantly from the algorithm's preset values, and continuing to calculate water age will lead to severe data distortion. Finally, the system will automatically exit the forced blending mode and revert to the energy efficiency priority mode based on direct municipal supply to ensure that the continuity of water supply to users is not affected by the verification process.

[0058] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0059] This embodiment provides an application example of ensuring water quality and balancing energy efficiency in residential communities during the summer based on the above system.

[0060] To verify the system's adjustment accuracy, water quality assurance capability, and fault diagnosis effectiveness under actual operating conditions, this embodiment constructs a typical secondary water supply simulation and test environment. The experiment focuses on examining how the system addresses residual chlorine decay through a forced mixing strategy under low flow (high retention risk) conditions at night, and verifies the interception capability of the power fingerprint verification mechanism in the event of valve failure.

[0061] Experimental scenario and parameter settings: Application Scenario: A 12-story residential building supplied with municipal water is equipped with a booster pump system. Summer ambient temperatures are high (average 30℃), resulting in rapid decay of residual chlorine in the water. Equipment Parameters: Variable frequency booster pump set 7: Rated power of a single pump Rated speed .

[0062] Flow stabilization compensation tank 6: Nominal total volume It has a rubber diaphragm airbag.

[0063] Pipeline conditions: Municipal water inlet pressure Fluctuation range 0.25-0.35MPa, user-set target pressure .

[0064] Control parameters: Water age safety threshold (Based on summer high temperature settings), reset threshold Power deviation threshold (5% of rated power).

[0065] Comparison Setup: To quantify the technical effects, three control experiments were set up: Comparative Example 1 (Traditional Superimposed Pressure Mode): Only municipal residual pressure is used for water supply, and water age monitoring and active mixing functions are not available.

[0066] Comparative Example 2 (Timed Cleaning Mode): The water pump is set to run at full speed for 30 minutes every 12 hours, without valve adjustment or fine pressure control.

[0067] Example (modulation of the present invention): Enable the full-function modules of volume identification, water age observation, dynamic mixing decision and impedance verification.

[0068] This embodiment utilizes the intelligent control system to execute the following operating process: Initialization and volume identification: At 2 AM, user water usage was detected, triggering the water pump to switch from sleep mode to startup. The volume identification module 200 captures the pressure rise slope within the first 3 seconds before startup. The pressure is 0.05 MPa / s. Based on the average injection flow rate, the effective water volume of the steady flow compensation tank 6 at the current moment is calculated. This serves as the baseline denominator for subsequent water age calculations.

[0069] Water age accumulation and monitoring, between 2 PM and 2 PM, due to municipal pressure (0.3MPa) is sufficient to meet the off-peak water demand of lower floors and some higher floors, and for energy conservation, it operates in energy efficiency priority mode. The bypass electric regulating valve 5 remains fully open, and the water pump is in sleep mode most of the time. The water age monitoring module 300 detects extremely low flow through the tank, classifying it as a stagnant condition, and the water age... It increases linearly over time. At 2 PM, the monitored value... Reaching 12 hours (i.e.) This triggers the alarm logic.

[0070] The dynamic blending decision execution module 400 determines that the water quality needs to be updated and switches to forced blending mode.

[0071] Calculate the control quantity: The system sets the target mixing ratio (That is, 30% of the flow goes through the water tank, and 70% goes through the bypass). Current total system flow requirement. .

[0072] Command issuance: Calculate the target opening degree command of the electric regulating valve using a formula. (Partially reduced to create impedance), while the feedforward control pump runs at 1800 rpm to compensate for pressure.

[0073] Impedance verification and fault simulation: Two seconds after the valve action command is issued, the impedance verification module 500 intervenes. Scenario A (Normal Operating Condition): Read the real-time active power of the water pump Calculations based on the theoretical model at the current speed of 1800 rpm and opening degree of 42%. .deviation The valve operation is deemed effective, and the allowable water age is determined. It begins to decrease according to the dilution formula.

[0074] Scenario B (Simulated Fault): The electric regulating valve is manually jammed and kept fully open. At this time, the pipeline resistance does not increase, but the water pump flow rate increases significantly at 1800 rpm. Actual measurement... .deviation The system determines that the actuator has failed, immediately stops updating the water age, and reports a valve jamming fault to prevent false water quality improvement data from misleading users.

[0075] In scenario A, after approximately 1.5 hours of mixed water supply, the stagnant water in the tank was gradually replaced. When monitoring... Descending to 2 hours ( When the throttling command is activated, the valve will be fully opened again, the water pump will stop, and the system will return to energy-saving mode.

[0076] The table below records key performance indicator data over a continuous 48-hour operating cycle: Evaluation indicators Comparative Example 1 (Traditional Stacking) Comparative Example 2 (Regular Cleaning) Example (of the present invention) illustrate Maximum water age >48 hours 12 hours 12 hours In the traditional model, the water in the tank cannot be renewed for a long time, resulting in the depletion of residual chlorine. Residual chlorine compliance rate 65% 95% 98% The embodiment maintains the disinfection activity of the water in the tank through dynamic mixing. User-side pressure fluctuations ±0.02MPa ±0.08MPa ±0.01MPa The timed cleaning mode causes a pressure surge when the pump is started and stopped; this invention achieves a smooth transition through valve-pump linkage. See attached document Figure 8 Comparison of water age change curves under different control strategies Figure 8 The relationship between time and water age in the steady flow compensation tank 6 is shown.

[0077] Dashed line (Comparative Example 1): Represents the traditional superimposed pressure mode, where the water age increases continuously in a step-like manner, only slightly decreasing during a very few peak water usage times, with the peak exceeding 40 hours, placing it in an extremely unsafe zone.

[0078] Solid line (example): Represents the mode of the present invention, exhibiting a regular sawtooth wave shape. Whenever the water age reaches the 12-hour threshold, the slope of the curve quickly turns negative (entering the mixing and dilution stage), until it resets after 2 hours, proving the effectiveness of the monitoring-decision-execution closed loop, which always maintains the water quality in a fresh state.

[0079] See attached document Figure 9 Pressure stability analysis diagram during forced blending process Figure 9 This demonstrates the instantaneous transition to forced mixing mode. User-side pressure response at any given moment.

[0080] Dotted line (no feedforward compensation): This indicates that the valve was closed slightly but the pump speed was not adjusted in time, causing the pressure to drop to 0.3MPa instantly. Subsequently, the PID control overshooted, and the oscillation time lasted for up to 30 seconds, affecting the user's water experience.

[0081] Solid line (in this invention): indicates enabling degree-based opening. After feedforward control, the pressure only fluctuated slightly (<0.01MPa) and quickly stabilized to the set value of 0.45MPa within 2 seconds, verifying the accuracy of the valve-pump coordinated control model.

[0082] The intelligent control system provided by this invention effectively solves the problem of water retention in traditional booster pump systems under low-flow conditions by introducing water age observation and active mixing mechanisms. Experimental data shows that compared with simple timed cleaning, this solution saves approximately 17% energy (from 135% to 112%) while ensuring the same water quality safety, and reduces pressure fluctuations by 87%. Simultaneously, the impedance verification mechanism based on power fingerprinting successfully fills the monitoring blind spot of low-cost valves lacking position feedback, achieving a reliable closed loop across the entire chain.

[0083] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A smart water supply control system with differentiated pressure and negative pressure-free operation, characterized in that, include: The data acquisition and control module is used to acquire the pressure signal of the water supply network and the operating data of the variable frequency booster pump set, calculate the system flow data based on the pump characteristic model, and send control commands to the variable frequency booster pump set and the bypass electric regulating valve. The volume identification module receives pressure signals and system flow data collected by the data acquisition and control module during the start-up phase of the variable frequency booster pump group, and determines the effective volume parameters of the flow stabilization compensation tank based on the pressure response characteristics and flow relationship. The water age observation module dynamically calculates the hydraulic residence time in the flow stabilization compensation tank using system flow data and the effective volume parameters. The mixing decision module is used to generate a forced mixing control strategy when the hydraulic retention time value reaches the water age safety threshold. The data acquisition and control module executes frequency commands and opening adjustment commands to drive the municipal influent and stagnant water to mix in proportion. The impedance verification module is used to verify the effectiveness of the mechanical action of the bypass electric regulating valve based on the real-time active power signal fed back after the opening adjustment command is issued, and to block the update of the hydraulic residence time value if it is invalid.

2. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 1, characterized in that, The data acquisition and control module internally stores a head-flow characteristic curve model of the variable frequency booster pump set at rated speed. The data acquisition and control module is configured to use the centrifugal pump similarity law to establish a nonlinear equation describing the mapping relationship between the actual head, motor speed and system flow rate at the current non-rated speed. Based on the real-time acquired user outlet water pressure signal and municipal inlet water pressure signal, the actual head is calculated, and then the system flow rate data is obtained by analyzing the nonlinear equation.

3. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 1, characterized in that, The volume identification module is configured to lock the start-up transient window of the variable frequency booster pump group from zero flow dormancy to the establishment of constant pressure, and extract the rate of change of the user outlet water pressure signal over time and the average injection flow rate within the start-up transient window; The volume identification module constructs a fluid stiffness model based on the gas polytropic process equation, calculates the instantaneous gas volume of the air bladder in the flow stabilization compensation tank using the ratio of the rate of change to the average injection flow rate, and determines the effective volume parameter based on the difference between the nominal total volume of the flow stabilization compensation tank and the instantaneous gas volume.

4. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 3, characterized in that, The volume identification module is also configured with an exponentially weighted moving average filtering logic, which is used to smoothly update the historically stored effective volume parameters using the effective volume instantaneous value calculated in the current startup event; when calculating the effective volume parameters, the volume identification module is also configured to deduct the structural dead zone volume of the flow stabilization compensation tank to ensure that the effective volume parameters only represent the volume of active water participating in the flow circulation.

5. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 1, characterized in that, The water age observation module is configured to switch between a retention accumulation mode and a flow dilution mode based on the size of the system flow data. When the system flow data is less than a preset micro-flow threshold, it enters the retention accumulation mode, and the hydraulic retention time increases linearly with time. When the system flow data is greater than the micro-flow threshold, it enters the flow dilution mode. Based on the mass balance principle, the water age observation module calculates the dilution term using the ratio of the system flow data to the effective volume parameter, so that the hydraulic retention time decreases exponentially with time.

6. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 1, characterized in that, The mixing decision module is configured to, when generating the forced mixing control strategy, first calculate the target opening command of the bypass electric regulating valve based on the preset mixing ratio coefficient and the current total system flow demand, using the inverse function of the valve flow characteristic function, so as to increase the hydraulic resistance of the bypass pipeline; at the same time, the mixing decision module calculates the feedforward speed command to compensate for pressure drop, and controls the variable frequency booster pump to draw water from the steady flow compensation tank for pressurization until the hydraulic residence time value is reduced to the preset reset threshold.

7. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 6, characterized in that, The reset threshold is set to a value less than the water age safety threshold; the mixing decision module is also configured to cancel the forced mixing control strategy when the hydraulic residence time value decreases to the reset threshold, control the bypass electric regulating valve to return to the fully open state and control the variable frequency booster pump group to hibernate, and the system returns to the energy efficiency priority control mode.

8. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 1, characterized in that, The impedance verification module has a pre-stored theoretical reference power model, which represents the polynomial function relationship between the shaft power of the variable frequency booster pump group and the motor speed when the bypass electric regulating valve is at a specific throttling opening. The impedance verification module is configured to compare the theoretical reference power calculated by substituting the real-time motor speed into the theoretical reference power model with the real-time active power fed back by the frequency converter to obtain the power deviation value.

9. The intelligent pressure-fed, non-negative-pressure water supply control system according to claim 8, characterized in that, The impedance verification module is configured to determine whether the absolute value of the power deviation exceeds a preset power deviation verification threshold; if it exceeds the power deviation verification threshold, it is determined that the bypass electric regulating valve has a mechanical fault or is stuck, and the impedance verification module then sends a freeze command to the water age observation module to stop updating the hydraulic residence time value and controls the system to exit the forced mixing control strategy.

10. A method for controlling intelligent pressure-fed, non-negative-pressure water supply, applied to an intelligent pressure-fed, non-negative-pressure water supply control system as described in any one of claims 1-9, characterized in that, Includes the following steps: At the moment the water supply system is started, the pressure change rate and the instantaneous flow rate are collected, and the current effective volume parameters of the flow stabilization compensation tank are calculated using the fluid stiffness model. Real-time monitoring of system flow data, combined with the effective volume parameters, is used to perform an integral calculation on the hydraulic residence time value in the flow stabilization compensation tank; Determine whether the hydraulic residence time value has reached the preset water age safety threshold; If the target is reached, a forced mixing control strategy is generated, outputting an opening adjustment command to control the bypass electric regulating valve to throttle, and driving the water pump to run in order to implement proportional mixing. After outputting the opening adjustment command, the deviation between the actual power and the theoretical reference power of the variable frequency booster pump set is calculated. The mechanical action of the bypass electric regulating valve is determined based on the deviation value; if it is invalid, the update of the hydraulic residence time value is blocked and an alarm is triggered.

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