Variable frequency constant pressure water supply device

Abstract

The utility model belongs to water supply equipment technical field, specifically disclose a kind of variable frequency constant pressure water supply equipment, including main water supply pipe, by frequency converter control's first water pump motor, pressure gauge, PLC, and shunt pipeline in main circuit;Shunt pipeline is equipped with water storage tank, by PLC control's second water pump motor, first solenoid valve and liquid level sensor, second solenoid valve is equipped on main circuit.Frequency converter is connected with three-phase power supply, low-power circuit is also provided between three-phase power supply and frequency converter, for reducing the power consumption of water supply equipment.The utility model realizes the energy-saving operation of on-demand energy supply by frequency conversion drive first water pump motor, also by PLC control shunt pipeline, use water storage tank to store energy in low water period, release energy in water peak period or main pump failure, greatly improve the flexibility and reliability of water supply and solve the problem of high standby energy consumption of existing constant pressure water supply equipment, and realize the low-power intelligent hibernation.

Description

Technical Field

[0001] This utility model belongs to the technical field of water supply equipment, and specifically relates to a variable frequency constant pressure water supply equipment. Background Technology

[0002] Constant pressure water supply equipment is a key component in building water supply and industrial production, aiming to maintain stable water pressure at the user end. Traditional variable frequency constant pressure water supply systems typically consist of a frequency converter, a water pump, and a pressure sensor. The frequency converter adjusts the pump speed to respond to pressure changes. However, to further ensure the stability of constant pressure water supply, designers have added a buffer tank to traditional constant pressure water supply systems to achieve rapid water supply response.

[0003] For example, Chinese patent CN223119166U discloses an energy-saving fully automatic variable frequency constant pressure water supply device. A pressure tank is installed on the water supply pipeline as a water storage container, working in conjunction with a water pump to achieve constant pressure water supply. Water enters the pressure tank from the top and is guided by an arc-shaped plate into a C-shaped mesh, where impurities are trapped and collected at the bottom of the mesh, facilitating cleaning. However, this design cannot automatically control the inlet and outlet processes of the pressure tank, and the water pump needs to operate continuously during the operation of the water supply device, resulting in high energy consumption. Utility Model Content

[0004] The purpose of this utility model is to overcome the defects in the existing technology and provide a variable frequency constant pressure water supply device.

[0005] This utility model provides a variable frequency constant pressure water supply device, including a main water supply pipe for connecting a water source and a user end. A first water pump motor and a pressure gauge are sequentially arranged on the main water supply pipe along the water flow direction. A frequency converter is connected to the three-phase terminals of the first water pump motor. The frequency converter is also connected to the pressure gauge. A PLC is also connected to the signal output terminal of the frequency converter. A bypass pipeline is also provided on the main water supply pipe, and a water storage tank is provided on the bypass pipeline. A second water pump motor is provided on the outlet side of the water storage tank for pumping the buffer water in the water storage tank into the user end. A level sensor is installed inside the water storage tank, a first solenoid valve is installed on the bypass pipeline, and a second solenoid valve is installed on the main water supply pipe. The level sensor, the first solenoid valve, and the second solenoid valve are respectively connected to the PLC. The L1, L2, and L3 terminals of the frequency converter are connected to a three-phase power supply. A low-power circuit is also provided between the three-phase power supply and the frequency converter to reduce the power consumption of the water supply equipment.

[0006] A further embodiment is that the bypass pipeline includes a bypass inlet pipe and a bypass outlet pipe; The first solenoid valve is located on the bypass inlet pipe, and one end of the bypass inlet pipe is connected to the main water supply pipe, while the other end of the bypass inlet pipe is connected to the inlet side of the water storage tank. The second water pump motor is located on the bypass outlet pipe, and one end of the bypass outlet pipe is connected to the outlet side of the water storage tank, while the other end of the bypass outlet pipe is connected to the main water supply pipe. The second solenoid valve is located on the main water supply pipe between the bypass inlet pipe and the bypass outlet pipe.

[0007] A further embodiment is that the connection point between the bypass inlet pipe and the main water supply pipe, and the connection point between the bypass outlet pipe and the main water supply pipe, are located between the first water pump motor and the pressure gauge.

[0008] A further embodiment is that the pressure gauge is a three-wire remote pressure gauge, and the 10V terminal, AVI terminal and GND terminal of the frequency converter are respectively connected to the 10V power line, AVI signal line and GND ground line of the three-wire remote pressure gauge.

[0009] A further embodiment is that the low-power circuit includes a pressure sensor, a controller, and an AC contactor; The pressure sensor is installed on the main water supply pipe and connected to the controller, and is used to monitor the water pressure of the main water supply pipe in real time and send the pressure signal to the controller. The controller has a preset pressure threshold. The controller is used to compare the received pressure signal with the pressure threshold and control the opening and closing of the AC contactor based on the comparison result: when the pressure signal is lower than the pressure threshold, the AC contactor is controlled to close; when the pressure signal is higher than the pressure threshold, the AC contactor is controlled to open. The AC contactor is located between the three-phase power supply and the frequency converter, and the AC contactor is electrically connected to both the three-phase power supply and the frequency converter.

[0010] A further embodiment is to install a circuit breaker between the three-phase power supply and the AC contactor, wherein the incoming terminal of the circuit breaker is connected to the three-phase power supply, and the outgoing terminal of the circuit breaker is connected to the incoming terminal of the AC contactor.

[0011] A further embodiment is that the controller is connected to an independent power supply; the independent power supply is taken from one phase of the three-phase power supply and provided after being isolated and stepped down by an AC / DC conversion module.

[0012] A further option is that the controller model is STM32L476.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention not only achieves energy-saving operation by driving the first water pump motor with frequency conversion, but also uses PLC to control the bypass pipeline, utilizing the water storage tank to store energy during low water usage periods and release energy during peak water usage periods or when the main pump fails, greatly improving the flexibility and reliability of water supply. Furthermore, a low-power circuit is set between the power supply and the frequency converter, fundamentally overcoming the inherent defect of high standby power consumption in existing equipment.

[0014] The bypass pipeline of this utility model consists of an independent inlet pipe and an outlet pipe. The PLC can precisely control the first solenoid valve to allow water to enter the storage tank and control the second water pump motor to allow water to exit the storage tank. Furthermore, the connection point of the bypass pipeline is located after the first water pump motor and before the pressure gauge, ensuring that the pressure monitoring point can simultaneously sense the water pressure changes of the main pipeline and the bypass pipeline, providing the PLC with comprehensive decision-making basis and avoiding monitoring blind spots.

[0015] This invention manages the main system power supply through an independent low-power control circuit. During periods of low water usage, it can completely cut off the power supply to high-power units such as frequency converters and PLCs, putting them into a zero-power sleep state. Only the ultra-low-power pressure sensor and controller remain in operation, thus reducing the overall standby power consumption. Attached Figure Description

[0016] The following figures are for illustrative purposes only and are not intended to limit the scope of the present invention. Figure 1 : Schematic diagram of the connection structure of this utility model; Figure 2 : Low-power circuit connection diagram; In the diagram: 1. Water source; 2. Main water supply pipe; 3. First water pump motor; 4. First solenoid valve; 5. Second solenoid valve; 6. Water storage tank; 7. Liquid level sensor; 8. Second water pump motor; 9. Frequency converter; 10. PLC; 11. Pressure gauge; 12. User terminal; 13. Pressure sensor; 14. Controller; 15. Three-phase power supply; 16. AC contactor; 17. Circuit breaker. Detailed Implementation

[0017] To make the objectives, technical solutions, design methods, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this utility model.

[0018] like Figure 1As shown, this utility model provides a variable frequency constant pressure water supply device, including a main water supply pipe 2 for connecting a water source 1 and a user terminal 12. A first water pump motor 3 and a pressure gauge 11 are installed sequentially on the main water supply pipe 2 along the water flow direction. The three-phase power line of the first water pump motor 3 is connected to the motor output terminal of a frequency converter 9. The power input terminal of the frequency converter 9 is connected to a three-phase power supply 15 through a low-power circuit. The pressure gauge 11 is connected to the analog input terminal of the frequency converter 9 to provide a pressure feedback signal. The signal output terminal of the frequency converter 9 is connected to a PLC 10 to report status and receive instructions. A bypass pipe is connected in parallel on the main water supply pipe 2. The bypass pipe is equipped with a water storage tank 6. A second water pump motor 8 is installed on the outlet side of the water storage tank 6 to replenish the water in the tank into the main water supply pipe 2 when needed. A level sensor 7 is installed inside the water tank, a first solenoid valve 4 is installed on the bypass pipeline, and a second solenoid valve 5 is installed on the main water supply pipeline. The level sensor 7, the first solenoid valve 4, and the second solenoid valve 5 are all connected to a PLC 10, which controls the opening and closing of the first solenoid valve 4 and the second solenoid valve 5 based on the water level. The frequency converter 9 adjusts the speed of the first water pump motor 3 according to the pressure feedback signal to achieve constant pressure water supply. The PLC 10 manages the filling and discharging logic of the water storage tank 6 in the bypass pipeline and cuts off the main system power supply through a low-power circuit during periods of low water consumption, thereby achieving intelligent and energy-saving operation. The bypass pipeline consists of a bypass inlet pipe and a bypass outlet pipe. A tee connector is used to connect one end of the bypass inlet pipe to the main water supply pipe 2. After connecting the first solenoid valve 4 in series with the bypass inlet pipe, the other end of the bypass inlet pipe is connected to the inlet side of the water storage tank 6. One end of the bypass outlet pipe is connected to the outlet side of the water storage tank 6, and after connecting the second water pump motor 8 in series, another tee connector is used to connect the other end of the bypass outlet pipe back to the main water supply pipe 2. The second solenoid valve 5 is connected in series on the main water supply pipe 2 located between these two tee connectors. The two tee connectors are installed downstream of the first water pump motor 3 and upstream of the pressure gauge 11. The water storage tank 6 acts as a buffer tank. When the water pressure in the main water supply pipe 2 is greater than the preset value, PLC10 can open the first solenoid valve 4 to store the excess water in the water storage tank 6. When the water pressure in the main water supply pipe 2 is less than the preset value, PLC10 can start the second water pump motor 8 to replenish the buffer water in the water storage tank 6 into the main water supply pipe 2.

[0019] In this embodiment, pressure gauge 11 is a three-wire remote pressure gauge. Its three leads are connected to corresponding terminals on the frequency converter 9. Specifically, the power supply line of pressure gauge 11 is connected to the +10V DC power supply terminal provided by the frequency converter 9, the signal line of pressure gauge 11 is connected to the analog input terminal of the frequency converter 9, and the ground line of pressure gauge 11 is connected to the common ground terminal of the frequency converter 9. The frequency converter 9 provides a precision reference power supply to power pressure gauge 11. The potentiometer inside pressure gauge 11 changes its resistance value with pressure changes, thereby outputting a 0-10V voltage signal proportional to the pressure and feeding it back to the frequency converter 9. By reading this signal value, the frequency converter 9 can accurately grasp the actual pressure of the pipeline network, forming the feedback basis for closed-loop control.

[0020] like Figure 2 As shown, the low-power circuit consists of a pressure sensor 13, a controller 14, an AC contactor 16, a circuit breaker 17, and an independent power supply. The circuit breaker 17 is connected in series with the three-phase power supply 15, and its output terminal is connected to the input terminal of the AC contactor 16. The output terminal of the AC contactor 16 is connected to the L1, L2, and L3 input terminals of the frequency converter 9. The pressure sensor 13 is installed on the main water supply pipe 2, and its output signal line is connected to the analog input pin of the controller 14. One digital output pin of the controller 14 controls the on / off state of the coil of the AC contactor 16 through the drive circuit. The power supply of the controller 14 is provided by an independent power supply, which is provided by an independent AC / DC conversion module. This AC / DC conversion module takes one phase and the neutral wire from the three-phase power supply 15 to obtain an AC220V input, converts it to DC5V or 3.3V, and then supplies power to the controller 14. The controller 14 continuously reads the signal from the pressure sensor 13 and compares it with an internally preset pressure threshold. When the monitored pressure is lower than the threshold, it indicates that there is a water demand. The controller 14 immediately outputs a high level to drive the AC contactor 16 to engage, supplying power to the inverter 9 and PLC 10. When the signal from the pressure sensor 13 is higher than the threshold, it indicates that the water demand has ended. The controller 14 disconnects the contactor 16, and the inverter 9 and PLC 10 are de-energized and enter a low-power sleep state. The circuit breaker 17 provides short-circuit and overload protection. The independent power supply design ensures that the monitoring unit can work continuously at any time, while the ultra-low power STM32L476 controller 14 ensures that the energy consumption of the monitoring process itself is extremely low.

[0021] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A variable frequency constant pressure water supply device, comprising a main water supply pipe (2) for connecting a water source (1) and a user end (12), characterized in that, A first water pump motor (3) and a pressure gauge (11) are sequentially installed on the main water supply pipe (2) along the water flow direction. A frequency converter (9) is connected to the three-phase terminals of the first water pump motor (3). The frequency converter (9) is also connected to the pressure gauge (11). A PLC (10) is also connected to the signal output terminal of the frequency converter (9). A bypass pipeline is also provided on the main water supply pipe (2), and a water storage tank (6) is provided on the bypass pipeline. A second water pump motor (8) is provided on the outlet side of the water storage tank (6) to pump the buffer water in the water storage tank (6) into the user end (12). A liquid level sensor (7) is installed inside the water storage tank (6), a first solenoid valve (4) is installed on the bypass pipeline, and a second solenoid valve (5) is installed on the main water supply pipe (2). The liquid level sensor (7), the first solenoid valve (4), and the second solenoid valve (5) are respectively connected to the PLC (10). The L1, L2, and L3 terminals of the inverter (9) are connected to a three-phase power supply (15). A low-power circuit is also provided between the three-phase power supply (15) and the inverter (9) to reduce the power consumption of the water supply equipment. The low-power circuit includes a pressure sensor (13), a controller (14), and an AC contactor (16). The pressure sensor (13) is installed on the main water supply pipe (2) and connected to the controller (14) for real-time monitoring of the water pressure of the main water supply pipe (2) and sending the water pressure information to the controller (14). The controller (14) is connected to the AC contactor (16) and controls the opening and closing of the AC contactor (16) based on the water pressure information. The AC contactor (16) is disposed between the three-phase power supply (15) and the frequency converter (9), and the AC contactor (16) is electrically connected to the three-phase power supply (15) and the frequency converter (9) respectively. A circuit breaker (17) is also provided between the three-phase power supply (15) and the AC contactor (16). The incoming terminal of the circuit breaker (17) is connected to the three-phase power supply (15), and the outgoing terminal of the circuit breaker (17) is connected to the incoming terminal of the AC contactor (16). The controller (14) is connected to an independent power supply; the independent power supply is taken from one phase of the three-phase power supply (15) and provided after being isolated and stepped down by the AC / DC conversion module; The controller (14) is an STM32L476.

2. The variable frequency constant pressure water supply equipment according to claim 1, characterized in that, The bypass pipeline includes a bypass inlet pipe and a bypass outlet pipe; The first solenoid valve (4) is located on the bypass water inlet pipe, and one end of the bypass water inlet pipe is connected to the main water supply pipe (2), and the other end of the bypass water inlet pipe is connected to the water inlet side of the water storage tank (6). The second water pump motor (8) is located on the bypass outlet pipe, and one end of the bypass outlet pipe is connected to the outlet side of the water storage tank (6), and the other end of the bypass outlet pipe is connected to the main water supply pipe (2). The second solenoid valve (5) is located on the main water supply pipe (2) between the bypass inlet pipe and the bypass outlet pipe.

3. The variable frequency constant pressure water supply equipment according to claim 2, characterized in that, The connection point between the bypass inlet pipe and the main water supply pipe (2) and the connection point between the bypass outlet pipe and the main water supply pipe (2) are located between the first water pump motor (3) and the pressure gauge (11).

4. The variable frequency constant pressure water supply equipment according to claim 1, characterized in that, The pressure gauge (11) is a three-wire remote pressure gauge. The 10V terminal, AVI terminal and GND terminal of the frequency converter (9) are respectively connected to the 10V power line, AVI signal line and GND ground line of the three-wire remote pressure gauge.

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