A flow detection circuit applied to a tee valve at a node of an energy storage fire-fighting pipe network

Abstract

The utility model relates to energy storage fire protection technical field discloses a flow detection circuit applied to energy storage fire protection pipe network node place tee bend valve, including a plurality of voltage stabilizing unit with power positive end electricity connection, voltage stabilizing unit stable power positive end voltage, the detection unit of water inlet, water outlet port is set respectively, voltage stabilizing unit is electrically connected with detection unit respectively, and detection unit is configured as the magnetic induction probe that produces analog signal with turbine cooperation, after analog signal is amplified through the amplification module and is converted waveform through the shaping module, converts digital pulse signal output to host processing. The utility model sets up the detection unit at water inlet port and water outlet port, makes fire extinguishing agent to drive the turbine rotation of being located at water inlet port and water outlet port respectively, makes turbine rotating speed and fire extinguishing agent flow rate proportionality, can know the independent flow data of water inlet port and water outlet port of tee bend valve, through comparing the flow data of different nodes, can know pipe network system failure in time, improves fire efficiency.

Description

Technical Field

[0001] This utility model relates to the field of energy storage fire protection technology, specifically to a flow detection circuit for a three-way valve applied at a node of an energy storage fire protection pipeline network. Background Technology

[0002] With the rapid development of the electrochemical energy storage industry, the safe operation of energy storage systems, especially the issue of thermal runaway fire suppression, has become a focus of industry attention. The precise and reliable release of gaseous fire extinguishing agents such as heptafluoropropane and perfluorohexanone, or fine water mist, is crucial for suppressing battery compartment fires. As the delivery channel for fire extinguishing agents, real-time monitoring of the fire suppression pipeline network's operational status is of paramount importance.

[0003] Currently, monitoring the flow rate in energy storage fire protection pipeline networks typically involves installing a single flow meter at the pump outlet or on the main pipeline. While this method can monitor the total system flow rate, it has significant blind spots. Because measurements are only taken on the main pipe, it's impossible to independently and precisely measure the flow rate of each branch at various nodes in the network (such as the critical component controlling water flow distribution—the three-way valve). Specifically, it's impossible to obtain independent flow rate data from the inlet and outlet ports of the three-way valve in real time. This monitoring blind spot prevents the early detection of hidden faults in the pipeline system, such as minor blockages in a branch or small leaks in the valve itself, thus affecting fire protection efficiency. The long-term accumulation of these hidden dangers can lead to serious consequences. Utility Model Content

[0004] This utility model addresses the problem that existing flow detection mechanisms for energy storage fire protection pipelines cannot promptly detect hidden faults in the pipeline system. It provides a flow detection circuit for a three-way valve at a node in an energy storage fire protection pipeline network. The specific technical solution is as follows: A flow detection circuit for a three-way valve at a node of an energy storage fire protection pipeline network. The flow detection circuit is installed at the inlet and outlet ports of the three-way valve and includes: Several voltage regulator units are electrically connected to the positive terminal of the power supply. The voltage regulator units can stabilize the input voltage at the positive terminal of the power supply. The detection units are respectively installed at the inlet and outlet ports. The voltage stabilizing unit is electrically connected to the detection unit. The detection unit is configured as a magnetic induction probe to generate analog signals in conjunction with the turbine. The analog signals are amplified by the amplification module and converted into waveforms by the shaping module before being converted into digital pulse signals and output to the host of the energy storage fire protection pipeline for processing.

[0005] Furthermore, the amplification module is configured with a chip U2 for amplifying analog signals. The +Vs and -Vs pins of chip U2 are electrically connected to the positive power supply terminal and the power supply ground terminal, respectively. The +IN and -IN pins of chip U2 are electrically connected to the positive and negative terminals of the analog signal, respectively. The -IN pin is electrically connected to the power supply ground terminal. The RG1 and RG2 pins of chip U2 are electrically connected to the adjustable resistor R3, respectively. The VOUT pin of chip U2 is electrically connected to the shaping module.

[0006] Preferably, the detection unit further includes an RC module connected in series with chip U2 and a magnetic probe connected in parallel with chip U2 and the RC module; One pin of the magnetic induction probe is electrically connected to the positive terminal of the power supply through resistor R1, and the other pin of the magnetic induction probe is electrically connected to both the -IN pin and the power supply ground terminal. When the magnetic induction probe is powered on, it generates an electromagnetic field to generate an analog signal with the turbine induction. One pin of the RC module is electrically connected to the magnetic probe, and the other pin of the RC module is electrically connected to the +IN pin, so that the induced current generated by the induced electromotive force flows from the RC module to the chip U2.

[0007] Preferably, the RC module is configured as a capacitor C2 for blocking the DC component in the induced current and a resistor R2 for regulating the voltage, connected in series.

[0008] Preferably, the detection unit further includes a bandpass LC filter electrically connected to the VOUT pin, and another pin of the bandpass LC filter is electrically connected to the shaping module.

[0009] Preferably, the shaping module is configured as a chip U3 for converting analog signals into digital signals. The VCC pin and GND pin of chip U3 are electrically connected to the positive power supply terminal and the power supply ground terminal, respectively. The TRIG pin and THRESH pin of chip U3 are connected in parallel and electrically connected to the bandpass LC filter. The OUT pin of chip U3 can drive the load. The RESET pin of chip U3 is electrically connected to the VCC pin. The CTRL pin of chip U3 is electrically connected to the capacitor C3 and the GND pin in sequence.

[0010] Preferably, the voltage stabilizing unit includes a first voltage regulator and a second voltage regulator. The IN pins of both the first and second voltage regulators are electrically connected to the positive terminal of the power supply, and the GND pins of both the first and second voltage regulators are electrically connected to the ground terminal of the power supply. The OUT pin of the first voltage regulator is electrically connected to the detection unit located at the water inlet port, and the OUT pin of the second voltage regulator is electrically connected to the detection unit located at the water outlet port.

[0011] Preferably, the three-way valve further includes a discharge port for discharging fire-fighting liquid at a fixed point, and the flow detection circuit further includes a solenoid valve drive unit for controlling the opening and closing of the discharge port.

[0012] As can be seen from the above technical solution, this utility model has the following beneficial effects: This invention incorporates detection units at the inlet and outlet ports, enabling the extinguishing agent flowing from the inlet to the outlet to drive turbines located at the inlet and outlet ports respectively. This ensures that the turbine speed is proportional to the flow rate of the extinguishing agent, allowing for the determination of independent flow data at the inlet and outlet ports of the three-way valve. By comparing the flow data at different nodes, hidden faults in the pipeline system can be identified in a timely manner, thereby improving fire-fighting efficiency and fire safety. Attached Figure Description

[0013] Figure 1 This is a partial circuit block diagram of an embodiment of the present utility model; Figure 2 This is a circuit schematic diagram of an embodiment of the present utility model; Figure 3 This is a circuit diagram of the monitoring unit in an embodiment of the present invention; Figure 4 This is a circuit diagram of the voltage regulator unit in an embodiment of this utility model.

[0014] In the diagram: 1. Voltage Regulator Unit; 11. First Voltage Regulator; 12. Second Voltage Regulator; 2. Detection Unit; 21. Magnetic Probe; 22. RC Module; 221. Resistor R2; 222. Capacitor C2; 24. Amplification Module; 241. Chip U2; 242. Adjustable Resistor R3; 25. Bandpass LC Filter; 26. Shaping Module; 261. Chip U3; 262. Capacitor C3; 3. Power Supply Positive Terminal; 4. Power Supply Ground Terminal; 5. Solenoid Valve Drive Unit; 6. Resistor R1; 7. Main Unit. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0017] This embodiment is a flow detection circuit for a three-way valve at a node of an energy storage fire protection pipeline network. Each node of the energy storage fire protection pipeline network is equipped with a three-way valve. The flow detection circuit is set at the inlet and outlet ports of the three-way valve, enabling it to detect the independent flow data at the inlet and outlet ports of the three-way valve, thereby performing refined detection on each node of the three-way valve.

[0018] like Figure 1 and Figure 2 As shown, the flow detection circuit includes: several voltage stabilizing units 1 electrically connected to the positive terminal 3 of the power supply, the voltage stabilizing units 1 being able to stabilize the input voltage of the positive terminal 3 of the power supply; detection units 2 respectively set at the inlet port and the outlet port, the voltage stabilizing units 1 being electrically connected to the detection units 2 respectively, the detection units 2 being configured as magnetic induction probes 21 for generating analog signals in conjunction with the turbine, the analog signals being amplified by the amplification module 24 and converted into waveforms by the shaping module 26, and then converted into digital pulse signals and output to the host 7 of the energy storage fire protection pipeline network for processing.

[0019] Specifically, the voltage stabilizing unit 1 installed at the inlet port and the voltage stabilizing unit 1 installed at the outlet port are connected in parallel. The parallel circuit of the two is connected in series with the resistor R16, so that the resistor R16 can adjust the voltage of the parallel circuit of the two and shunt the current to it. When the input voltage of the positive terminal 3 of the power supply changes, the two can stably output a fixed voltage. The two detection units 2 are connected in series with the two voltage stabilizing units 1 respectively, so that the input voltage of the two detection units 2 is the same fixed voltage output by the voltage stabilizing unit 1. This allows the detection units 2 to work under a stable voltage, improving the signal-to-noise ratio of the analog signal and the accuracy of the flow measurement results.

[0020] Secondly, as is known from common knowledge in this field, the magnetic induction probe 21 consists of a turbine and an electromagnet. The rotation of the turbine cuts the magnetic field lines generated by the electromagnet, causing a change in its magnetic flux, which in turn generates an induced electromotive force. The magnitude and direction of this induced electromotive force change continuously, its waveform is approximately a sine wave, and its frequency is proportional to the turbine's rotational speed, forming an analog signal carrying turbine rotational speed information. Furthermore, the magnetic induction probe 21 is connected in series with the amplification module 24 and the shaping module 26, so that the analog signals at both the inlet and outlet ports can be amplified by the amplification module 24, making them amplified enough to be processed by subsequent shaping. The shaping module 26 processes the voltage level; secondly, the shaping module 26 compares the input amplified analog signal with a preset threshold voltage. When the input voltage is higher than the upper limit of the threshold, the shaping module 26 outputs a high level; when the input voltage is lower than the lower limit of the threshold, the shaping module 26 outputs a low level, thereby converting the analog signal into a standard square wave signal, and thus obtaining the liquid flow rate at the inlet and outlet ports. This is then sent to the host 7 of the energy storage fire protection pipeline network for processing, thereby obtaining the flow rate data at the inlet and outlet ports of the nodes, and thus improving the energy storage fire protection pipeline network's ability to perform refined monitoring of the operating status of each node.

[0021] When the host 7 of the energy storage fire protection pipeline detects different flow data at different nodes (different three-way valves), it can promptly know that there is a leak between the nodes or a slight blockage in the pipeline, and then repair it in time.

[0022] like Figure 3 As shown, the amplification module 24 is configured with a chip U2241 for amplifying analog signals. The +Vs and -Vs pins of the chip U2241 are electrically connected to the positive power supply terminal 3 and the power supply ground terminal 4, respectively. The +IN and -IN pins of the chip U2241 are electrically connected to the positive and negative terminals of the analog signal, respectively. The -IN pin is electrically connected to the power supply ground terminal 4. The RG1 and RG2 pins of the chip U2241 are electrically connected to the adjustable resistor R3242, respectively. The VOUT pin of the chip U2241 is electrically connected to the shaping module 26.

[0023] Specifically, chip U2241 is an AD620 amplifier chip, typically packaged in an 8-pin package. Pin 7 of chip U2241 is the +Vs pin, directly connected to the positive terminal 3 of the power supply, and pin 4 is the -Vs pin, directly connected to the ground terminal 4 of the power supply, thus supplying power to the chip. Pin 3 of chip U2241 is the +IN pin, directly connected to the positive terminal of the analog signal, and pin 2 is the -IN pin, directly connected to the negative terminal of the analog signal, thus transmitting the analog signal to chip U2241 for amplification. Pins 1 and 8 of chip U2241... The pins RG1 and RG2 are used to connect to the two pins of the adjustable resistor R3242, enabling the adjustment of the gain of the chip U2241, i.e., the amplification factor of the analog signal. Specifically, increasing the resistance of the adjustable resistor R3242 decreases the gain of the chip U2241, and decreasing the resistance of the adjustable resistor R3242 increases the gain of the chip U2241, so that the voltage of the analog signal can be amplified to a voltage that the shaping model can process. Secondly, the 6th pin of the chip U2241 is the VOUT pin, which is used to electrically connect to the shaping module 26, and can output the amplified analog signal to the shaping module 26.

[0024] Furthermore, the detection unit 2 also includes an RC module 22 connected in series with the chip U2241 and a magnetic induction probe 21 connected in parallel with the chip U2241 and the RC module 22; one pin of the magnetic induction probe 21 is electrically connected to the positive terminal 3 of the power supply through a resistor R16, and the other pin of the magnetic induction probe 21 is electrically connected to both the -IN pin and the power supply ground terminal 4. When the magnetic induction probe 21 is energized, it generates an electromagnetic field to generate an analog signal in conjunction with the turbine induction; one pin of the RC module 22 is electrically connected to the magnetic induction probe 21, and the other pin of the RC module 22 is electrically connected to the +IN pin, so that the induced current generated by the induced electromotive force flows from the RC module 22 to the chip U2241.

[0025] Specifically, RC module 22 is connected in series with chip U2241, and the series circuit formed by the two is connected in parallel with magnetic probe 21. This makes the induced electromotive force generated by magnetic probe 21 the power supply for the series circuit formed by RC module 22 and chip U2241, thereby causing the induced current generated by the induced electromotive force to flow from RC module 22 to chip U2241. Secondly, as is known from common knowledge in the art, magnetic probe 21 includes an electromagnet and an induction coil. The electromagnet is electrically connected to the positive terminal 3 and the ground terminal 4 of the power supply through resistor R16, so that the electromagnet forms a stable electromagnetic field through a stable voltage, and then the turbine cuts the stable electromagnetic field to generate an induced electromotive force, i.e., an analog signal. The induced electromotive force generates a sinusoidal induced current in the induction coil, which flows through RC module 22 to chip U2241, so that RC module 22 can only allow the induced current of magnetic probe 21 to pass through.

[0026] Furthermore, the RC module 22 is configured to have a capacitor C2222 for blocking the DC component in the induced current and a resistor R2221 for regulating the voltage connected in series.

[0027] Specifically, one end of capacitor C2222 is electrically connected to magnetic probe 21, and the other end is connected in series with resistor R2221 and chip U2241. The induced current generated by magnetic probe 21 is alternating current, which is filtered by capacitor C2222 to remove the DC component of the induced current. The AC component of the induced current is then transmitted to chip U2241 through resistor R2221, thereby reducing the noise of the analog signal. Secondly, resistor R2221 and capacitor C2222 are connected in series. The capacitive reactance of capacitor C2222 is inversely proportional to the frequency of the induced current. The higher the frequency of the induced current, the lower the capacitive reactance of capacitor C2222, the smaller the total resistance, the higher the voltage of resistor R2221, and the larger the induced current. Conversely, the lower the frequency of the induced current, the higher the capacitive reactance of capacitor C2222, the larger the total resistance, the lower the voltage of resistor R2221, and the smaller the induced current.

[0028] Furthermore, the detection unit 2 also includes a bandpass LC filter 25 electrically connected to the VOUT pin, and another pin of the bandpass LC filter 25 is electrically connected to the shaping module 26.

[0029] Specifically, in the bandpass LC filter 25, the inductor and capacitor resonate at a preset frequency (determined according to production requirements), allowing the preset frequency to pass while attenuating other frequencies. Secondly, the bandpass LC filter 25 has three pins: its input terminal LCIN is electrically connected to the VOUT pin for inputting the amplified analog signal; its output terminal LCOUT is electrically connected to the shaping module 26 for outputting the filtered analog signal; and its ground terminal LCGND is electrically connected to the capacitor used for filtering, allowing high-frequency signals in the analog signal higher than the preset frequency to be guided to ground by the capacitor, thus outputting an analog signal of the preset frequency.

[0030] Furthermore, the shaping module 26 is configured with a chip U3261 for converting analog signals into digital signals. The VCC pin and GND pin of the chip U3261 are electrically connected to the positive power supply terminal 3 and the power supply ground terminal 4, respectively. The TRIG pin and THRESH pin of the chip U3261 are connected in parallel and electrically connected to the bandpass LC filter 25. The OUT pin of the chip U3261 can drive the load. The RESET pin of the chip U3261 is electrically connected to the VCC pin. The CTRL pin of the chip U3261 is electrically connected to the capacitor C3262 and the GND pin in sequence.

[0031] Specifically, chip U3261 is an NE555 chip, typically packaged in an 8-pin package, used to convert a sine wave analog signal into a square flat wave digital signal. Pin 1 of chip U3261 is the GND pin, connected to power supply ground (pin 4); pin 8 is the VCC pin, connected to the positive power supply (pin 3); the output LCOUT of bandpass LC filter 25 is electrically connected to both pins 2 and 6; pin 2 is the trigger pin TRIG, which triggers when the low-voltage portion of the analog signal below 1 / 3 of the power supply voltage is triggered, causing the timer output to toggle to high; and pin 6 is the threshold pin TH. RESH is triggered when the high-voltage portion of the analog signal, which is 2 / 3 higher than the power supply voltage, is activated, causing the output to go low and convert the analog signal into a digital signal. Pin 3 is the output terminal OUT for the digital signal that outputs a square wave. Pin 4 is the reset terminal RESET, which is active low and used to force a reset (clear to zero). It is usually connected to VCC to avoid false triggering. Pin 5 is the control terminal CTRL, which is connected in series with capacitor C3262 (0.01μF) and then electrically connected to GND. It is used to change the comparator reference voltage in chip U3261, thereby affecting the output square wave of the digital signal.

[0032] like Figure 4 As shown, the voltage regulator unit 1 includes a first voltage regulator 11 and a second voltage regulator 12. The IN pins of both the first voltage regulator 11 and the second voltage regulator 12 are electrically connected to the positive terminal 3 of the power supply. The GND pins of both the first voltage regulator 11 and the second voltage regulator 12 are electrically connected to the ground terminal 4 of the power supply. The OUT pin of the first voltage regulator 11 is electrically connected to the detection unit 2 located at the water inlet port, and the OUT pin of the second voltage regulator 12 is electrically connected to the detection unit 2 located at the water outlet port.

[0033] Specifically, voltage regulator 1 is connected in series with resistor R16 and connected to the positive terminal 3 of the power supply, so that resistor R16 can adjust the voltage of voltage regulator 1. In voltage regulator 1, the first voltage regulator 11 and the second voltage regulator 12 are connected in parallel so that the voltages of the two are the same. The first voltage regulator 11 can provide a stable DC voltage to the magnetic sensor 21 set at the water inlet port, and the second voltage regulator 12 can provide a stable and the same DC voltage to the magnetic sensor 21 set at the water outlet port, so that the electromagnetic fields generated by the two magnetic sensor 21 are stable and the same, thereby stabilizing the induced electromotive force generated by the two, and thus stabilizing the digital signal output at the water inlet port and the digital signal at the water outlet port.

[0034] Furthermore, the three-way valve also includes a discharge port for discharging fire-fighting liquid at a fixed point, and the flow detection circuit also includes a solenoid valve drive unit 5 for controlling the opening and closing of the discharge port.

[0035] Specifically, the inlet and outlet ports of the three-way valve are connected in series and connected to the pipeline in the energy storage network. The fire extinguishing agent in the pipeline flows from the inlet port to the outlet port. When a leak occurs in the pipeline, the digital signals at the inlet ports at different locations will differ. These signals are transmitted to the host 7 of the energy storage fire protection network for processing, thereby obtaining the difference in flow data between the inlet and outlet ports at different nodes, and thus determining the location of the leak between nodes. When the discharge port is opened by the solenoid valve drive unit 5, the fire extinguishing agent flowing in from the inlet port flows out from the discharge port and the outlet port, making the flow rate at the outlet port at that node lower than that at the inlet port. This indicates that the discharge port has been opened, improving the monitoring of the flow rate and fire protection status of each node by the energy storage fire protection network.

[0036] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

[0037] The technologies, shapes, and structures not described in detail in this utility model are all known technologies.

Claims

1. A flow detection circuit for a three-way valve applied at a node of an energy storage fire protection pipeline network, characterized in that, The flow detection circuit is installed at the inlet and outlet ports of the three-way valve, and the flow detection circuit includes: A plurality of voltage regulator units (1) electrically connected to the positive terminal (3) of the power supply, wherein the voltage regulator units (1) are capable of stabilizing the input voltage of the positive terminal (3) of the power supply; The detection units (2) are respectively set at the water inlet port and the water outlet port. The voltage stabilizing unit (1) is electrically connected to the detection unit (2). The detection unit (2) is configured as a magnetic induction probe (21) for cooperating with the turbine to generate an analog signal. The analog signal is amplified by the amplification module (24) and the waveform is converted by the shaping module (26) and then converted into a digital pulse signal and output to the host (7) of the energy storage fire protection pipeline for processing.

2. The flow detection circuit according to claim 1, characterized in that: The amplification module (24) is configured as a chip U2 (241) for amplifying the analog signal. The +Vs pin and -Vs pin of the chip U2 (241) are electrically connected to the positive terminal (3) and the ground terminal (4) of the power supply, respectively. The +IN pin and -IN pin of the chip U2 (241) are electrically connected to the positive terminal and the negative terminal of the analog signal, respectively. The -IN pin is electrically connected to the ground terminal (4) of the power supply. The RG1 pin and RG2 pin of the chip U2 (241) are electrically connected to the adjustable resistor R3 (242), respectively. The VOUT pin of the chip U2 (241) is electrically connected to the shaping module (26).

3. The flow detection circuit according to claim 2, characterized in that: The detection unit (2) further includes an RC module (22) connected in series with the chip U2 (241) and a magnetic probe (21) connected in parallel with the chip U2 (241) and the RC module (22); One pin of the magnetic sensor (21) is electrically connected to the positive terminal (3) of the power supply through a resistor R1 (6), and the other pin of the magnetic sensor (21) is electrically connected to both the -IN pin and the power supply ground terminal (4). When the magnetic sensor (21) is powered on, it generates an electromagnetic field to generate an analog signal with the turbine induction. One pin of the RC module (22) is electrically connected to the magnetic sensor (21), and the other pin of the RC module (22) is electrically connected to the +IN pin, so that the induced current generated by the induced electromotive force flows from the RC module (22) to the chip U2 (241).

4. The flow detection circuit according to claim 3, characterized in that: The RC module (22) is configured to have a capacitor C2 (222) for blocking the DC component in the induced current and a resistor R2 (221) for regulating the voltage connected in series.

5. The flow detection circuit according to claim 2, characterized in that: The detection unit (2) also includes a bandpass LC filter (25) electrically connected to the VOUT pin, and another pin of the bandpass LC filter (25) is electrically connected to the shaping module (26).

6. The flow detection circuit according to claim 5, characterized in that: The shaping module (26) is configured as a chip U3 (261) for converting the analog signal into a digital signal. The VCC pin and GND pin of the chip U3 (261) are electrically connected to the positive power supply terminal (3) and the power supply ground terminal (4) respectively. The TRIG pin and THRESH pin of the chip U3 (261) are connected in parallel and electrically connected to the bandpass LC filter (25). The OUT pin of the chip U3 (261) can drive the load. The RESET pin of the chip U3 (261) is electrically connected to the VCC pin. The CTRL pin of the chip U3 (261) is electrically connected to the capacitor C3 (262) and the GND pin in sequence.

7. The flow detection circuit according to claim 2, characterized in that: The voltage stabilizing unit (1) includes a first voltage regulator (11) and a second voltage regulator (12). The IN pins of the first voltage regulator (11) and the second voltage regulator (12) are both electrically connected to the positive terminal (3) of the power supply. The GND pins of the first voltage regulator (11) and the second voltage regulator (12) are both electrically connected to the ground terminal (4) of the power supply. The OUT pin of the first voltage regulator (11) is electrically connected to the detection unit (2) located at the water inlet port. The OUT pin of the second voltage regulator (12) is electrically connected to the detection unit (2) located at the water outlet port.

8. The flow detection circuit according to claim 1, characterized in that, The three-way valve also includes a discharge port for discharging fire-fighting liquid at a fixed point, and the flow detection circuit also includes a solenoid valve drive unit (5) for controlling the opening and closing of the discharge port.

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