High-precision liquid leakage detection equipment

Abstract

The utility model provides high-precision liquid leakage detection equipment, which comprises a constant current source output circuit, a liquid leakage induction line and a control unit, the constant current source output circuit is used for outputting constant current; the liquid leakage induction line comprises a switch unit, a first detection branch and a second detection branch; the first detection branch is coupled with the output end of the constant current source output end circuit and is coupled to a grounding end through the switch unit; the power supply is coupled to the second detection branch through the switch unit and is grounded; the control unit is in coupling connection with the constant current source output circuit, the switch unit, the first detection branch and the second detection branch. According to the device, constant and high-precision current is output through the constant current source output circuit, the influence of current fluctuation in the detection process is small during liquid leakage detection, and leakage alarm can be achieved more accurately.

Description

Technical Field

[0001] The utility model relates to the technical field of measurement and control equipment, in particular to a high-precision liquid leakage detection device. Background Art

[0002] Existing data centers and other places with a large number of equipment usually require the use of water cooling systems to cool electronic equipment. The water cooling system removes heat from the equipment through liquid cooling lines for cooling. The coolant itself is the conductor medium. When the liquid cooling line ages or breaks, causing the coolant to leak, a conductive path will be formed between the lines of different potentials on the circuit board, causing an electrical short circuit. The short circuit will instantly generate a large current, which will not only damage the electronic components, but may also cause safety accidents such as fire.

[0003] The existing method usually cooperates with a leakage sensing line and a constant voltage source circuit to detect the leakage by detecting the voltage when the coolant leaks and seeps into the leakage sensing line. However, voltage detection alone has great limitations and is easily affected by current interference, making it difficult to meet the needs of high-precision liquid leakage detection. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the present invention proposes a high-precision liquid leakage detection device, which can reduce interference during detection and achieve more accurate leakage alarm.

[0005] The technical solution of the present utility model is achieved as follows:

[0006] A high-precision liquid leakage detection device, comprising

[0007] A constant current source output circuit, which is used to output a constant current;

[0008] a liquid leakage sensing line, the liquid leakage sensing line comprising a switch unit, a first detection branch, and a second detection branch, the first detection branch being coupled to the output end of the constant current source output circuit and coupled to the ground end through the switch unit; the power supply being coupled to the second detection branch through the switch unit and grounded;

[0009] A control unit is coupled to the constant current source output circuit, the switch unit, the first detection branch, and the second detection branch.

[0010] A further technical solution of this embodiment is that the constant current source output circuit includes a negative feedback circuit for detecting and monitoring the output current.

[0011] A further technical solution of this embodiment is that the constant current source output circuit includes an operational amplifier U1, an operational amplifier U2, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a load resistor RL; the inverting input terminal of the operational amplifier U1 is grounded through the resistor R1 and coupled to the output terminal through the resistor R2, the non-inverting input terminal is coupled to the 3.3V power supply through the resistor R3, and its output terminal is coupled to the first detection branch and the non-inverting input terminal of the operational amplifier U2 through the load resistor RL, the inverting input terminal of the operational amplifier U2 is coupled to the output terminal, and the output terminal is coupled to the non-inverting input terminal of the operational amplifier U2 through the resistor R4.

[0012] A further technical solution of this embodiment is that the first detection branch includes a first wire and a second wire connected to each other, the first wire is coupled to the output end of the constant current source output circuit, and the second wire is coupled to the ground end through the switch unit; the second detection branch includes a third wire and a fourth wire connected to each other, the third wire is coupled to the power supply through the switch unit, and the fourth wire is connected to the ground end; the outer skin of the first wire and the third wire is an insulating and waterproof material, and the outer skin of the second wire and the fourth wire is a conductive silicone.

[0013] A further technical solution of this embodiment is that the first conductive wire, the second conductive wire, the third conductive wire and the fourth conductive wire are arranged adjacent to each other.

[0014] A further technical solution of this embodiment is that the first detection branch further includes a reference resistor R5, and the second wire is coupled to the ground terminal through the resistor R5.

[0015] A further technical solution of this embodiment is that the second detection branch further includes a reference resistor R6, the fourth wire is coupled to the ground terminal via the resistor R6, and the accuracy of the resistor R6 is 0.1%.

[0016] A further technical solution of this embodiment is that the switch unit includes a first switch and a second switch, the second wire is coupled to the ground terminal through the first switch, and the third wire is coupled to the power supply through the second switch.

[0017] A further technical solution of this embodiment is that the first switch and the second switch are configured as single-pole single-throw switches.

[0018] Compared with the prior art, the utility model has the following advantages:

[0019] The utility model outputs a constant and high-precision detection current through a constant current source output circuit to detect the leakage sensing line, and determines whether there is liquid leakage by detecting the voltage and current of the leakage sensing line. During the detection process, it is less affected by current fluctuations and can realize leakage alarm more accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the implementation methods or the description of the prior art. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is a circuit diagram of a high-precision liquid leakage detection device of the utility model;

[0022] Figure 2 It is the equivalent circuit diagram of the constant current source output circuit in the utility model;

[0023] Figure 3 This is the equivalent circuit diagram of the leakage sensing line in the present utility model when there is no leakage;

[0024] Figure 4 This is an equivalent circuit diagram of the leakage sensing line in the present utility model when leakage occurs;

[0025] Figure 5 This is a wiring diagram of a high-precision liquid leakage detection device of the utility model;

[0026] Figure identification: 1-constant current source output circuit; 2-leakage sensing line; 21-first wire; 22-second wire; 23-third wire; 24-fourth wire; 3-control center; A1-first voltage; A2-second voltage; A3-third voltage. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this utility model and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0030] like Figures 1 to 5 As shown, the embodiment of the present invention discloses a high-precision liquid leakage detection device, including a constant current source output circuit 1 for outputting a constant current, a leakage sensing line 2, and a control unit 3; the leakage sensing line 2 includes a switch unit, a first detection branch, and a second detection branch. The first detection branch is coupled to the output end of the constant current source output circuit 1 and is coupled to the ground end through the switch unit; the power supply is coupled to the second detection branch through the switch unit and is grounded; the control unit 3 is coupled to the constant current source output circuit 1, the switch unit, the first detection branch, and the second detection branch. The constant current source output circuit 1 can output a stable and high-precision constant current, providing a detection reference for the leakage sensing line. Compared with the existing constant voltage source detection circuit that can only use voltage to determine leakage, the constant current source output circuit 1 can also determine leakage by current. It is less affected by current fluctuations during the detection process and can more accurately implement leakage alarms. It can be understood by those skilled in the art that the control center 3 determines whether leakage occurs by regularly sampling the voltage or current on the sensing line 2 and comparing them. The selection of the leakage sensing line and the control chip can be adjusted according to the actual project requirements. The following describes a high-precision liquid leakage detection device proposed in this embodiment:

[0031] like Figure 1As shown, in order to ensure the reliability and stability of the output current of the constant current source output circuit, the negative feedback principle is used in this embodiment to construct the constant current source output circuit. When the circuit is working, by monitoring the output current and comparing it with the preset reference current, the working state of the current control element is dynamically adjusted, thereby achieving a constant and high-precision current output. Specifically, the constant current source output circuit includes an operational amplifier U1, an operational amplifier U2, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a load resistor RL; the inverting input terminal of the operational amplifier U1 is grounded through the resistor R1 and coupled to the output terminal through the resistor R2, the non-inverting input terminal is coupled to the 3.3V power supply through the resistor R3, and its output terminal is coupled to the first detection branch and the non-inverting input terminal of the operational amplifier U2 through the load resistor RL. The inverting input terminal of the operational amplifier U2 is coupled to the output terminal, and the output terminal is coupled to the non-inverting input terminal of the operational amplifier U2 through the resistor R4. For operational amplifier U1, due to the existence of negative feedback, according to the virtual short and virtual open principle, the voltages at its non-inverting input and inverting input are approximately equal; for operational amplifier U2, its non-inverting input voltage is related to the output of operational amplifier U1 through load resistor RL, and its inverting input is connected to the output, forming a voltage follower characteristic; through the above relationship and the virtual short and virtual open characteristics of the operational amplifier, the following is obtained: Figure 2 As shown in the equivalent circuit diagram, since VOUT is the feedback voltage, the following formula can be obtained:

[0032]

[0033] According to the circuit amplification principle, the voltage above the load resistor RL is as follows:

[0034] V=2*V in =3.3v+V out

[0035] Therefore, the voltage applied to the load resistor RL is constant at V-VOUT=3.3V, so the output current of the constant current source output circuit is constant.

[0036] like Figure 3 As shown, the first detection branch includes a first wire 21 and a second wire 22 connected to each other. The first wire 21 is coupled to the output end of the constant current source output circuit, and the second wire 22 is coupled to the ground end via a switch unit. The second detection branch includes a third wire 23 and a fourth wire 24 connected to each other. The third wire 23 is coupled to the power supply via a switch unit, and the fourth wire 24 is connected to the ground end. The outer surface of the first wire 21 and the third wire 23 is made of an insulating and waterproof material, while the outer surface of the second wire 22 and the fourth wire 24 is made of conductive silicone. The first wire 21, the second wire 22, the third wire 23, and the fourth wire 24 are arranged adjacent to each other. When liquid leaks, the liquid can cover the four wires, thereby conducting between the second wire 22 and the fourth wire 24.

[0037] When there's no leakage, the control center sends a signal to close the switch unit. The control center samples the first and third voltage points A1 and A3 to determine if the cable is broken. It also samples the second and third voltage points A2 and A3 to calculate the voltage drop across the entire cable segment. Specifically, the cable voltage drop A = A2 - A3, and the loop current I = A3 / R6. Therefore, the resistance of the leaking line segment R = A / I. The line length L = R / R1 is then calculated using the line resistance R1. The line resistance R1 is determined by the selected leak detection sensing cable and varies depending on the model.

[0038] When a leak occurs, liquid invades the leakage sensing line. The control center disconnects the switch unit through program control during sampling. Only the constant current source supplies power to the entire circuit, and the current is constant. However, at this time, the first voltage A1 will continue to decrease as the degree of leakage increases. By sampling the first voltage A1, it can be determined whether there is a leak, and the leakage distance can be calculated in combination with the voltages at points A2 and A3.

[0039] like Figure 4 As shown, the current does not shunt on the fourth conductor 24 and does not flow through A2. Therefore, the voltage at sampling point A2 is equal to the voltage at the leakage point (red circle). Therefore, the voltage drop of the entire cable can be calculated by sampling the voltages at points A2 and A3: A = A2 - A3; the loop current: I = A3 / R6; and the resistance of the leakage line segment: R = A / I. The leakage position, L leak = R / R l, can then be calculated using the line resistance R l.

[0040] When leakage occurs, the loop load increases and the first voltage A1 decreases. Since the leaked liquid has impedance, the more liquid leaks, the lower the first voltage A1. Different sensitivity levels can be set based on this characteristic.

[0041] To ensure detection accuracy, the first detection branch includes a reference resistor R5, through which the second wire 22 is coupled to the ground terminal. The second detection branch includes a reference resistor R6, through which the fourth wire 24 is coupled to the ground terminal. The accuracy of resistor R6 is 0.1%, thereby improving the measurement accuracy of the entire system.

[0042] In this embodiment, the switch unit includes a first switch S1 and a second switch S2. The second wire 22 is coupled to the ground terminal through the first switch S1, and the third wire 23 is coupled to the power supply through the second switch S2. Specifically, the first switch S1 and the second switch S2 are configured as single-pole single-throw switches.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high-precision liquid leakage detection device, characterized in that: include A constant current source output circuit, which is used to output a constant current; a liquid leakage sensing line, the liquid leakage sensing line comprising a switch unit, a first detection branch, and a second detection branch, the first detection branch being coupled to the output end of the constant current source output circuit and coupled to the ground end through the switch unit; the power supply being coupled to the second detection branch through the switch unit and grounded; A control unit is coupled to the constant current source output circuit, the switch unit, the first detection branch, and the second detection branch.

2. The high-precision liquid leakage detection device according to claim 1, characterized in that: The constant current source output circuit includes a negative feedback circuit for detecting and monitoring the output current.

3. The high-precision liquid leakage detection device according to claim 2, characterized in that: The constant current source output circuit includes an operational amplifier U1, an operational amplifier U2, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a load resistor RL; the inverting input terminal of the operational amplifier U1 is grounded through the resistor R1 and coupled to the output terminal through the resistor R2, the non-inverting input terminal is coupled to the 3.3V power supply through the resistor R3, and the output terminal is coupled to the first detection branch and the non-inverting input terminal of the operational amplifier U2 through the load resistor RL, the inverting input terminal of the operational amplifier U2 is coupled to the output terminal, and the output terminal is coupled to the non-inverting input terminal of the operational amplifier U2 through the resistor R4.

4. The high-precision liquid leakage detection device according to claim 1, characterized in that: The first detection branch includes a first wire and a second wire connected to each other, the first wire is coupled to the output end of the constant current source output circuit, and the second wire is coupled to the ground end through the switch unit. The second detection branch includes a third wire and a fourth wire connected to each other, the third wire is coupled to the power supply through the switch unit, and the fourth wire is connected to the ground end; the outer skin of the first wire and the third wire is an insulating and waterproof material, and the outer skin of the second wire and the fourth wire is a conductive silicone.

5. The high-precision liquid leakage detection device according to claim 4, characterized in that: The first conductive line, the second conductive line, the third conductive line and the fourth conductive line are arranged adjacent to each other.

6. The high-precision liquid leakage detection device according to claim 4, characterized in that: The first detection branch further includes a reference resistor R5, and the second wire is coupled to the ground terminal through the resistor R5.

7. The high-precision liquid leakage detection device according to claim 4, characterized in that: The second detection branch further includes a reference resistor R6 , through which the fourth wire is coupled to the ground terminal. The accuracy of the resistor R6 is 0.1%.

8. The high-precision liquid leakage detection device according to claim 4, characterized in that: The switch unit includes a first switch and a second switch. The second wire is coupled to the ground terminal through the first switch, and the third wire is coupled to the power supply through the second switch.

9. The high-precision liquid leakage detection device according to claim 8, characterized in that: The first switch and the second switch are configured as single-pole single-throw switches.

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