Constant-pressure water supply control method, system, equipment and medium

Abstract

The invention relates to the technical field of constant-pressure water supply control, in particular to a constant-pressure water supply control method, system, equipment and medium, which comprises the following steps: adjusting the output frequency of a frequency converter through a controller based on the pressure deviation between a preset water supply pressure target value and actually measured actual water supply pressure, and controlling the rotating speed of a water pump; the closed-loop control on the water supply pressure is realized; in response to the change of the water load, when the operation of a single water pump cannot meet the water supply pressure target value, the operation mode is automatically switched between single-pump variable-frequency operation and multi-pump cooperative operation; and monitoring the water level of the water source, and performing linkage control on water replenishing operation and operation permission of the water pump based on the water level state. The water supply system has the beneficial effect that the pressure stability, the equipment operation reliability and the energy efficiency level of the water supply system are improved on the whole.

Description

Technical Field

[0001] This invention relates to the field of constant pressure water supply control technology, and in particular to a constant pressure water supply control method, system, equipment and medium. Background Technology

[0002] Constant pressure water supply technology is a key component of modern heating and water supply systems. Its core objective is to maintain stable pipeline pressure to meet varying water demands from users. With the widespread application of variable frequency speed control technology and programmable logic controllers (PLCs), traditional constant pressure water supply systems have evolved from simple power frequency start-stop control to automatic control systems employing a combination of variable frequency pumps and power frequency pumps.

[0003] However, existing constant pressure water supply control systems still have several problems that urgently need to be solved in practical applications. First, at the moment of switching between fixed frequency pumps and variable frequency pumps, the lack of a precise coordination mechanism can easily cause drastic fluctuations in pipeline pressure, disrupting water supply stability. Second, the system's automation and reliability are insufficient. For example, the pump start-up and de-starting logic often relies on simple instantaneous pressure judgment, leading to frequent pump starts and stops, shortening equipment lifespan. In addition, the interlocking protection logic between water tank level control and pump operation is not perfect, posing a risk of pump "dry running." These problems collectively restrict the further improvement and application of constant pressure water supply systems. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0005] In a first aspect, the present invention provides a constant pressure water supply control method, which includes adjusting the output frequency of a frequency converter and controlling the speed of a water pump by means of a controller based on the pressure deviation between a preset target value of water supply pressure and the measured actual water supply pressure, so as to achieve closed-loop control of water supply pressure.

[0006] In response to changes in water load, when the operation of a single water pump cannot meet the target value of water supply pressure, the operating mode is automatically switched between single pump frequency conversion operation and multi-pump coordinated operation.

[0007] Monitor the water source level and, based on the water level status, coordinate the water replenishment operation and the operation permit of the water pump;

[0008] The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction.

[0009] As a preferred embodiment of the constant pressure water supply control method of the present invention, the switching determination condition is based on a comprehensive determination of the pressure deviation and the real-time operating status of the frequency converter.

[0010] As a preferred embodiment of the constant pressure water supply control method of the present invention, the switching determination conditions include pump increase determination conditions and pump decrease determination conditions;

[0011] The condition for adding a pump is: after a single water pump operates at its upper frequency limit in variable frequency mode, the actual water supply pressure remains lower than the target water supply pressure value.

[0012] The pump reduction judgment condition is: in the multi-pump collaborative operation mode, after the frequency of the water pump in variable frequency operation drops to the preset lower limit frequency, the actual water supply pressure still continues to be higher than the target value of water supply pressure.

[0013] As a preferred embodiment of the constant pressure water supply control method of the present invention, the method further includes:

[0014] After the switching determination conditions are met, the switching control logic does not immediately issue a switching execution command, but introduces a delayed confirmation process.

[0015] The switching execution command is issued only after the switching determination condition has been continuously met for a predetermined delay time.

[0016] As a preferred embodiment of the constant pressure water supply control method of the present invention, the method includes: water level status linkage control, comprising:

[0017] When the water level is below the first threshold, the water supply valve is opened to replenish water;

[0018] When the water level is higher than the second threshold, close the water supply valve to stop water supply;

[0019] When the water level is below the third threshold, all water pumps must be forcibly stopped from starting or from stopping any currently running water pumps.

[0020] The third threshold is lower than the first threshold.

[0021] In a preferred embodiment of the constant pressure water supply control method of the present invention, the delay time of the delay confirmation process is a configurable parameter.

[0022] The delay time is set based on the inertial time constant of the system's water supply network, which is used to filter out instantaneous fluctuations in water supply pressure and ensure that the switching execution command is triggered by continuous changes in water load.

[0023] In a preferred embodiment of the constant pressure water supply control method of the present invention, the switching execution command is configured to coordinate the timing of the frequency converter and the power grid frequency.

[0024] By controlling the output frequency curve of the frequency converter, a seamless switching effect can be achieved where the water supply pressure fluctuation is less than a predetermined threshold during the switching action.

[0025] In a second aspect, the present invention provides a constant pressure water supply control system, comprising: a control module, used to adjust the output frequency of a frequency converter and control the speed of a water pump based on the pressure deviation between a preset target value of water supply pressure and the measured actual water supply pressure, so as to achieve closed-loop control of the water supply pressure;

[0026] The switching module is used to respond to changes in water load and automatically switch the operating mode between single pump frequency conversion operation and multi-pump coordinated operation when the operation of a single water pump cannot meet the target value of water supply pressure.

[0027] The monitoring module is used to monitor the water level of the water source and, based on the water level status, to control the water replenishment operation and the operation permission of the water pump.

[0028] The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction.

[0029] Thirdly, the present invention provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0030] Fourthly, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described above.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: by introducing switching judgment conditions based on pressure deviation and inverter status and a delayed confirmation process, the automatic and smooth switching of the water pump between different operating modes is realized, effectively avoiding malfunctions and pipeline pressure shocks caused by instantaneous load fluctuations; at the same time, combined with the graded water level linkage control mechanism, while ensuring automatic water replenishment of the water tank, the risks of water pump dry running and water tank overflow are completely prevented, thereby significantly improving the pressure stability, equipment operation reliability and energy efficiency of the water supply system as a whole. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart illustrating the constant pressure water supply control method.

[0034] Figure 2 This is a process flow diagram with control points.

[0035] Figure 3 This is a block diagram for PID closed-loop control.

[0036] Figure 4 is a schematic diagram of the electrical circuit.

[0037] Figure 5 Flowchart for the control of standby pump activation and deactivation.

[0038] Figure 6 Logic diagram for interlocking conditions that prevent water pumps from operating.

[0039] Figure 7 This is the logic diagram for water level limit control. Detailed Implementation

[0040] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0041] Example 1, referring to Figure 1 This is the first embodiment of the present invention, which provides a constant pressure water supply control method, including:

[0042] S100: Based on the pressure deviation between the preset target water supply pressure and the actual measured water supply pressure, the controller adjusts the output frequency of the frequency converter to control the water pump speed, thereby achieving closed-loop control of the water supply pressure.

[0043] S200: In response to changes in water load, when the operation of a single water pump cannot meet the target value of water supply pressure, the operating mode is automatically switched between single pump frequency conversion operation and multi-pump coordinated operation. The switching of the operating mode is implemented by a switching control logic, which includes at least a switching judgment condition and a switching execution instruction.

[0044] S300: Monitors the water level of the water source and controls the water replenishment operation and the operation permission of the water pump based on the water level status.

[0045] It should be noted that in heating or water supply systems in residential communities and commercial buildings, users' water load exhibits significant periodic and random fluctuations, such as a surge in water consumption during morning and evening peak hours and a sharp decrease at night. Traditional constant pressure water supply control often employs simple pressure switches or single PID fixed-frequency control, which is ill-suited to handle such drastic fluctuations: during peak water consumption periods, insufficient network pressure can easily occur, affecting the end-user experience; during off-peak periods, excessive pressure may damage pipeline equipment. Furthermore, when water pumps switch between different operating modes (such as single-pump variable frequency and multi-pump power frequency coordination), improper logic can generate severe pressure shocks and water hammer effects, damaging the pumps and the network. In addition, if the water level monitoring of the source water tank is not effectively interlocked with the operation of the water pumps, there is a risk of the pumps running dry and burning out, or the water tank overflowing.

[0046] Therefore, to address the aforementioned issues of water supply pressure stability, equipment safety, and system adaptability, this method constructs a multi-level, intelligently interconnected closed-loop control system through steps S100-S300: real-time PID regulation ensures the stability of the base pressure; based on precise judgment conditions and a delayed confirmation mechanism, smooth and uninterrupted switching of pump operating modes is achieved, effectively expanding the system's water supply adjustment range and avoiding equipment impact; and a comprehensive water level interlocking protection provides a safeguard for the safe operation of the entire system. The coordinated work of these three elements jointly achieves high stability of water supply pressure, high reliability of equipment switching, and high safety of system operation under complex and changing loads.

[0047] Example 2, refer to Figures 1 to 7 As an embodiment of the present invention, a constant pressure water supply control method is provided based on the above embodiment.

[0048] In this embodiment of the application, step S100, based on the pressure deviation between the preset target water supply pressure and the measured actual water supply pressure, adjusts the output frequency of the frequency converter through the controller to control the water pump speed, thereby achieving closed-loop control of the water supply pressure, including the following steps A1-A2:

[0049] Understandably, the controller is a programmable logic controller (PLC), and one frequency converter controls two or more water pumps.

[0050] A1: The preset target value of water supply pressure SP is set based on the maximum elevation of the heating system service area with a margin.

[0051] It should be noted that the allowance is the pressure value corresponding to a 5-meter water column.

[0052] For example, the maximum elevation of the service area of ​​a certain heating system is 20 meters, plus a 5-meter margin, so the corresponding preset target value of water supply pressure is 0.25 MPa.

[0053] A2: Closed-loop control of water supply pressure is achieved through PID control algorithm. The PID control algorithm calculates the proportional, integral, and derivative terms of the pressure deviation and outputs a control signal.

[0054] Understandably, when the actual water supply pressure is lower than the preset target value, the system will increase the water supply pressure by increasing the pump speed; conversely, it will decrease the pump speed. The proportional term is proportional to the current pressure deviation and is used to quickly adjust the control signal according to the magnitude of the current deviation. A larger proportional coefficient will result in a faster system response to the deviation. The integral term considers the accumulation of pressure deviation over a period of time and aims to eliminate the steady-state error of the system. That is, when the system has a small deviation over a long period of time, the integral term will gradually accumulate and adjust the control signal until the deviation is eliminated. A longer integral time will result in a weaker integral effect, and vice versa. The derivative term is based on the rate of change of the pressure deviation and is used to predict the trend of deviation change and suppress further changes in deviation by adjusting the control signal in advance. A longer derivative time will enhance the derivative effect and help improve the stability of the system.

[0055] It should be noted that the parameters of the PID control algorithm are tuned using engineering tuning methods to balance the system's response speed and stability.

[0056] Specifically, such as Figure 2 As shown, after the system is put into operation, tap water is pressurized and supplied by variable frequency water pumps (P101A / P101B). Tap water valves V6 to V9 are used to simulate the water load in the service area of ​​the heating system (opening all of them means entering the peak water consumption period, at which time the controller will automatically adjust the pump frequency or increase the number of pumps in operation to meet the constant pressure requirement); manual valve V5 can be used to simulate tap water consumption. When the water consumption is high, water is automatically replenished through V101. LI101 is used to measure the water level in the water tank. The real-time water supply pressure is measured by pressure transmitter PT101 and fed back to PLC. After being calculated by PID controller, it is converted into a 4-20mA standard current signal and sent to frequency converter to control the pump speed, thereby realizing the constant value control of water supply pressure.

[0057] Furthermore, such as Figure 3As shown, a PT101 pressure transmitter is installed at the water pump outlet pipe to measure the actual water supply pressure. This signal is converted into a standard electrical signal by the transmitter and then acquired by the PLC analog module. Inside the PLC, this value is subtracted from the pressure setpoint to obtain the deviation e. The PID controller takes the deviation e as input and performs proportional, integral, and derivative operations on e. The result is then converted into a standard electrical signal representing the frequency value by the analog output module and sent to the frequency converter, thereby controlling the water pump speed. The water pump speed is then readjusted by the controlled object to correct the water supply pressure that deviates from the preset target value, thus forming a closed-loop control of the water supply pressure.

[0058] In this embodiment of the application, in step S200, in response to changes in water load, when the operation of a single water pump cannot meet the target value of water supply pressure, the operating mode is automatically switched between single-pump variable frequency operation and multi-pump coordinated operation. The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction, including the following steps B1-B4:

[0059] It should be noted that the switching judgment condition is based on a comprehensive judgment of pressure deviation and real-time operating status of the frequency converter. It can be understood that pressure deviation reflects the demand side of the system, while the real-time operating status of the frequency converter reflects the capacity side of the system. Furthermore, the frequency converter status (such as output frequency) directly reflects the output of the currently operating water pump. Combining the two can make the judgment more accurate and reliable.

[0060] Specifically, by using a single frequency converter to control the soft start and stop of two water pumps, the cost of electrical equipment can be effectively reduced while ensuring the setpoint control of the water supply pressure. Simultaneously, the adjustable range of the control system can be significantly increased. As shown in Figure 4(a), each of the two water pumps has two operating modes: frequency conversion and mains frequency bypass. Based on the power supply conditions of the frequency converter and the requirements for safe and reliable system operation, it is essential to ensure that mains frequency and frequency conversion cannot start simultaneously. That is, contactors KM3 and KM1 in the figure cannot be energized simultaneously, and similarly, contactors KM4 and KM2 cannot be energized simultaneously. Furthermore, the two water pumps cannot operate in frequency conversion mode simultaneously to avoid overloading the frequency converter. The control circuit for this frequency conversion one-to-two pump design is shown in Figure 4(b). When the SA selector switch is in the manual position, the two water pumps can be started or stopped directly in mains frequency or frequency conversion mode via a button. When the SA selector switch is in the automatic position, the PLC controls the contactors through intermediate relays KA1 to KA4. The interlocking relationship of the contactors ensures the mutual disconnection and safety protection between mains frequency, frequency conversion, and the frequency conversion of the two pumps.

[0061] B1: Switching judgment conditions include pump increase judgment conditions and pump decrease judgment conditions;

[0062] The condition for adding a pump is: after a single water pump operates at its upper frequency limit in variable frequency mode, the actual water supply pressure remains lower than the target water supply pressure value.

[0063] It is understandable that running at the upper limit frequency (such as 50Hz) means that the speed regulation capability of a single water pump has been exhausted, and the fact that the actual water supply pressure is still lower than the target value proves that there is indeed a capacity gap. Based on this, it is necessary and reasonable to add more pumps.

[0064] The pump reduction judgment condition is: in the multi-pump collaborative operation mode, after the frequency of the water pump in variable frequency operation drops to the preset lower limit frequency, the actual water supply pressure still continues to be higher than the target value of water supply pressure.

[0065] It is understandable that when the frequency of a variable frequency pump drops to the preset lower limit frequency, it means that the variable frequency pump is already in the minimum energy consumption maintenance operation state. The fact that the actual water supply pressure is still higher than the target water supply pressure value indicates that the minimum output of a single pump still exceeds the demand. Therefore, reducing the number of pumps at this time can save energy and prevent excessive pressure.

[0066] It should be noted that the pressure setting range should generally not be too narrow. For example, if the preset target value of water supply pressure is 0.25MPa, the lower limit is generally around 0.21MPa. If the lower limit is too high (the pressure setting range is too narrow), it will easily cause frequent pump start-stop.

[0067] B2: After the switching determination condition is met, the switching control logic does not immediately issue a switching execution command, but introduces a delayed confirmation process;

[0068] The switching execution command is issued only after the switching determination condition has been continuously met for a predetermined delay time.

[0069] B3: The delay time for the delayed confirmation process is a configurable parameter;

[0070] The delay time is set based on the inertial time constant of the system's water supply network, which is used to filter out instantaneous fluctuations in water supply pressure and ensure that the switching execution command is triggered by continuous changes in water load.

[0071] like Figure 5 As shown, by using the delayed confirmation logic of the switching conditions, the "false switching" of the water pump can be effectively avoided, reducing the wear and tear on the life of the water pump and motor; at the same time, by controlling the frequency at the switching point, the smooth switching of the water pump can be guaranteed (i.e., the water pump switching does not affect the stability of the water supply pressure).

[0072] It should be noted that under normal circumstances, when water consumption is low, pump M2 is in a stopped state, and pump M1 alone can meet the pressure control requirements under frequency conversion control. However, during peak water consumption periods, water consumption increases and water pressure decreases. To meet the pressure setting requirements, the PID controller will gradually increase the calculation result to improve the water supply pressure. When the frequency converter output frequency rises to 50Hz, but the water pressure is still insufficient (the water replenishment pressure value is far from the set value and can never reach the set pressure, and the pump body is always in the on state), after a delay confirmation, the control logic switches M1 to bypass power frequency operation, and at the same time, the frequency converter output frequency drops to zero. Then, M2 is put into frequency conversion PID mode operation, so that both water pumps run simultaneously (power frequency plus frequency conversion) to improve the water supply capacity and control the water supply pressure to return to the set value.

[0073] Furthermore, after the peak water usage period, water consumption decreases and water pressure drops. The PID calculation output will cause the inverter output frequency to continuously decrease. When the output frequency is lower than the set lower limit, but the water supply pressure is still too high (higher than the set lower limit and basically does not decrease, i.e., it is in a stable state), the inverter mode of M2 will be stopped first, the inverter output frequency will be increased to 50Hz, then the M1 pump will be stopped from operating at the mains frequency, and the M1 inverter will be started at the same time to restore the single pump inverter regulation mode.

[0074] Ideally, in a water supply network, a user's brief opening / closing of a tap can cause a sudden drop / rise in pressure. By introducing a "delayed confirmation" mechanism, it is possible to effectively distinguish between such instantaneous fluctuations and continuous trends representing real load changes. Compared to a simple system that acts immediately upon meeting the conditions, this system offers significant advantages in stability and reliability.

[0075] B4: The switching execution command is configured to coordinate the activation timing of the frequency converter and the power grid frequency;

[0076] By controlling the output frequency curve of the frequency converter, a seamless switching effect can be achieved where the water supply pressure fluctuation is less than a predetermined threshold during the switching action.

[0077] It is understandable that water supply pressure fluctuations less than the predetermined threshold means controlling the fluctuations within ±0.02MPa.

[0078] In this embodiment of the application, step S300 involves monitoring the water source level and, based on the water level status, controlling the water replenishment operation and the operation permit of the water pump, including the following steps C1-C3:

[0079] C1: When the water level is lower than the first threshold, the water supply valve is opened to supply water, where the first threshold is the minimum water supply limit.

[0080] Understandably, the first threshold can be set to 0.2 meters above the upper edge of the water tank replenishment pump outlet pipe.

[0081] C2: When the water level is higher than the second threshold, close the water supply valve to stop water supply, where the second threshold is the upper limit for water supply.

[0082] Understandably, the second threshold can be set to 0.5 meters above the upper edge of the water tank replenishment pump outlet pipe. When the water level in the water tank exceeds the lower edge of the maximum value by 0.15 meters, the water replenishment solenoid valve is closed. The maximum value is determined by the lower edge of the water tank overflow hole.

[0083] C3: When the water level is below the third threshold, all water pumps must be prohibited from starting or stopped from running. The third threshold is the prohibited water level.

[0084] The third threshold is lower than the first threshold.

[0085] It should be noted that when the water level drops to the third threshold, it indicates that regular water replenishment can no longer maintain the water level, the system recognizes that a danger has occurred, and thus triggers a forced pump shutdown. The setting of the third threshold is also based on the physical structure of the water tank, ensuring that it is above the pump inlet but far below the safe operating water level, providing a final buffer between low water level and pump damage.

[0086] It's important to understand that when the water level drops and reaches the third threshold, a shutdown is triggered, meaning the pumps stop. Conversely, when the water level rises and crosses the third threshold, a resumption is triggered, allowing the pumps to restart. The specific logic is as follows: Figure 6 As shown.

[0087] Understandably, the purpose of water level control is to maintain the water level between its upper and lower limits. If the water level is too high, overflow may occur. Prolonged overflow at unattended water supply stations not only wastes water resources but can also lead to equipment flooding or even submersion, which is an extremely dangerous accident that must be avoided at all costs. If the water level is too low, the pump will run dry, preventing the heat generated by friction between the pump impeller and the pump body from dissipating, causing rapid overheating and severe damage to the equipment. Therefore, the water supply valve is required to open when the water level is below the lower limit and close when the water level is above the upper limit. Specifically, as shown below... Figure 7 As shown.

[0088] In summary, this method, by introducing switching judgment conditions based on pressure deviation and inverter status, along with a delayed confirmation process, enables automatic and seamless switching of the water pump between different operating modes, effectively avoiding malfunctions and pipeline pressure surges caused by instantaneous load fluctuations. Simultaneously, combined with a tiered water level linkage control mechanism, it ensures automatic water tank replenishment while completely preventing the risks of pump dry running and tank overflow, thus significantly improving the overall pressure stability, equipment reliability, and energy efficiency of the water supply system.

[0089] Example 3 illustrates a schematic scheme for a constant pressure water supply control method. It should be noted that the technical solution of this constant pressure water supply control system belongs to the same concept as the technical solution of the constant pressure water supply control method described above. Details not described in detail in this embodiment can be found in the description of the technical solution of the constant pressure water supply control method described above.

[0090] This embodiment also provides a constant pressure water supply control system, including:

[0091] The control module is used to control the water pump speed by adjusting the output frequency of the frequency converter through the controller based on the pressure deviation between the preset target value of water supply pressure and the measured actual water supply pressure, so as to achieve closed-loop control of water supply pressure.

[0092] The switching module is used to respond to changes in water load and automatically switch the operating mode between single pump frequency conversion operation and multi-pump coordinated operation when the operation of a single water pump cannot meet the target value of water supply pressure.

[0093] The monitoring module is used to monitor the water level of the water source and, based on the water level status, to control the water replenishment operation and the operation permission of the water pump.

[0094] The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction.

[0095] This embodiment also provides an electronic device suitable for high-temperature constant-pressure water supply control, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to realize the constant-pressure water supply control method proposed in the above embodiment.

[0096] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, it implements the constant pressure water supply control method proposed in the above embodiments.

[0097] The storage medium proposed in this embodiment and the constant pressure water supply control method proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0098] Based on the above description of the implementation methods, those skilled in the art will clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0099] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A constant pressure water supply control method, characterized in that: include, Based on the pressure deviation between the preset target water supply pressure and the actual measured water supply pressure, the controller adjusts the output frequency of the frequency converter to control the water pump speed, thereby achieving closed-loop control of the water supply pressure. In response to changes in water load, when the operation of a single water pump cannot meet the target value of water supply pressure, the operating mode is automatically switched between single pump variable frequency operation and multi-pump coordinated operation. Monitor the water source level and, based on the water level status, coordinate the water replenishment operation and the operation permit of the water pump; The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction.

2. The constant pressure water supply control method as described in claim 1, characterized in that: The switching determination criteria are based on a comprehensive assessment of the pressure deviation and the real-time operating status of the frequency converter.

3. The constant pressure water supply control method as described in claim 2, characterized in that: The switching determination conditions include pump increase determination conditions and pump decrease determination conditions; The pump addition determination condition is: after a single water pump operates to the upper limit frequency in variable frequency mode, the actual water supply pressure is still lower than the target value of the water supply pressure. The pump reduction determination condition is: in the multi-pump collaborative operation mode, after the frequency of the water pump in variable frequency operation drops to the preset lower limit frequency, the actual water supply pressure still continues to be higher than the target value of the water supply pressure.

4. The constant pressure water supply control method as described in claim 3, characterized in that: The method also includes, After the switching determination condition is met, the switching control logic does not immediately issue the switching execution command, but introduces a delayed confirmation process. The switching execution command is issued only after the switching determination condition has been continuously satisfied for a predetermined delay time.

5. The constant pressure water supply control method as described in claim 4, characterized in that: The water level-based linkage control includes, When the water level is below the first threshold, the water supply valve is opened to replenish water; When the water level is higher than the second threshold, the water supply valve is closed to stop water supply; When the water level is below the third threshold, all water pumps must be forcibly stopped from starting or from stopping any currently running water pumps. The third threshold is lower than the first threshold.

6. The constant pressure water supply control method as described in claim 4, characterized in that: The delay time for the delay confirmation process is a configurable parameter; The delay time is set based on the inertial time constant of the system's water supply network, which is used to filter out instantaneous fluctuations in water supply pressure and ensure that the switching execution command is triggered by continuous changes in water load.

7. A constant pressure water supply control method as described in any one of claims 1-6, characterized in that: The switching execution command is configured to coordinate the timing of the inverter's connection to the power grid frequency; By controlling the output frequency curve of the frequency converter, a seamless switching effect can be achieved where the water supply pressure fluctuation is less than a predetermined threshold during the switching action.

8. A constant pressure water supply control system, using the method described in any one of claims 1-7, characterized in that, include: The control module is used to control the water pump speed by adjusting the output frequency of the frequency converter through the controller based on the pressure deviation between the preset target value of water supply pressure and the measured actual water supply pressure, so as to achieve closed-loop control of water supply pressure. The switching module is used to respond to changes in water load and automatically switch the operating mode between single pump frequency conversion operation and multi-pump coordinated operation when the operation of a single water pump cannot meet the target value of water supply pressure. The monitoring module is used to monitor the water level of the water source and, based on the water level status, to control the water replenishment operation and the operation permission of the water pump. The switching of the operating mode is implemented by a switching control logic, which includes at least a switching determination condition and a switching execution instruction.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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