A flow sensor based on the resistance properties of graphene

Abstract

The utility model discloses a flow sensor based on graphene resistance characteristic relates to flow sensor technical field, including water meter and pipeline, the water meter is installed on the pipeline, install on the pipeline sensor assembly with the pipeline intercommunication, the sensor assembly is including encapsulation layer, is provided with graphene sensing element in encapsulation layer, graphene sensing element both ends lead out have the wire, graphene sensing element both ends are equipped with the flexible carrier, graphene sensing element is fixed in encapsulation layer through the flexible carrier, the wire is connected with resistance detection circuit electricity, resistance detection circuit and analog -to -digital converter electric connection, the sensitivity of flow sensor is higher phase, is more suitable for the detection of small flow, and graphene has very high chemical stability and biocompatibility, in water meter application, graphene sensor is usually encapsulated in the protective layer, will not directly contact with water, will not cause the pollution of water quality.

Description

Technical Field

[0001] This utility model relates to the field of flow sensor technology, and specifically to a flow sensor based on the resistive properties of graphene. Background Technology

[0002] With the rapid development of the smart water industry, the accuracy of water metering remains a crucial basis for water companies and users to calculate water fees. Various innovations have been made in metering methods, and flow sensors are currently widely used in many fields. Common flow sensors include ultrasonic flow sensors and electromagnetic flow sensors. Ultrasonic flow sensors calculate flow rate by measuring the time difference of ultrasonic waves propagating in a fluid. They have advantages such as non-contact measurement and wide applicability, but they suffer from insufficient sensitivity in detecting small flow rates and are relatively expensive. Electromagnetic flow sensors, based on Faraday's law of electromagnetic induction, are more accurate in measuring conductive fluids, but they have certain requirements regarding the conductivity of the fluid, and their accuracy decreases when measuring low-conductivity fluids. Utility Model Content

[0003] Purpose of the utility model: The technical problem to be solved by this utility model is to provide a flow sensor based on the resistive properties of graphene, which solves the problem of insufficient sensitivity of existing flow sensors in detecting small flow rates.

[0004] Technical solution

[0005] To solve the above problems, the technical solution provided by this utility model is as follows:

[0006] A flow sensor based on the resistive properties of graphene includes a water meter and a pipe. The water meter is installed on the pipe, and a sensor assembly communicating with the pipe is installed on the pipe. The sensor assembly includes an encapsulation layer, within which a graphene sensing element is disposed. Wires extend from both ends of the graphene sensing element, and flexible carriers are sleeved at both ends of the graphene sensing element. The graphene sensing element is fixed within the encapsulation layer by the flexible carriers. The wires are electrically connected to a resistance detection circuit, and the resistance detection circuit is electrically connected to an analog-to-digital converter.

[0007] Furthermore, the graphene sensing element is a rectangular thin sheet.

[0008] Furthermore, the graphene sensing element is disposed on the central plane of the pipe.

[0009] Furthermore, the length direction of the graphene sensing element is the same as the liquid flow direction in the pipe.

[0010] Furthermore, the flexible carrier is fixed at both ends of the graphene sensing element, and the flexible carrier covers both ends of the graphene sensing element.

[0011] Furthermore, the flexible carrier and the graphene sensing element are fixed by friction engagement, clamping, or clipping.

[0012] Furthermore, the encapsulation layer has a cavity, the flexible carrier is fixed in the cavity, and the shape of the cavity is consistent with the shape of the pipe.

[0013] Furthermore, the inner diameter of the cavity is the same as the inner diameter of the pipe.

[0014] Furthermore, the encapsulation layer, except for the cavity, is a solid structure.

[0015] Furthermore, the water meter is also equipped with a processor.

[0016] Beneficial effects

[0017] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0018] The flow sensor provided by this invention has higher sensitivity and is more suitable for detecting small flow rates, extending its service life to over eight years. Furthermore, graphene possesses extremely high chemical stability and biocompatibility, ensuring it will not pollute water quality during application. By deriving changes in flow velocity within the pipe through resistance variations, and further calculating the flow rate, flow detection using resistance changes can accurately and efficiently correspond to real-time changes in flow velocity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0020] Figure 2 This is an exploded view of Embodiment 1 of this utility model;

[0021] Figure 3 This is a circuit diagram of Embodiment 1 of the present invention.

[0022] 1. Water meter; 2. Pipeline; 3. Sensor assembly; 4. Graphene sensing element;

[0023] 5. Flexible carrier; 6. Encapsulation layer; 7. Protective cover; 8. Wire; Detailed Implementation

[0024] To make the technical solution 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.

[0025] Example 1

[0026] Combined with appendix Figure 1-3 A flow sensor based on the resistive properties of graphene includes a water meter 1, which is installed on a pipe 2. A sensor assembly 3 connected to the pipe 2 is installed on the pipe 2. The sensor assembly 3 is installed on the middle section of the pipe 2 near the water meter 1. The sensor assembly 3 includes an encapsulation layer 6 connected to the pipe 2. A flexible carrier 5 is disposed inside the encapsulation layer 6. A graphene sensing element 4 is disposed inside the flexible carrier 5. The graphene sensing element is a rectangular thin sheet made of graphene material.

[0027] Graphene possesses high sensitivity, high wear resistance, high corrosion resistance, high stability, and good biocompatibility. Therefore, the graphene sensing element 4 can remain in the pipe 2 for a long time without affecting the liquid inside the pipe 2. At the same time, since the resistance of the graphene material changes accordingly with the flow rate of the fluid it contacts, the flow rate of the fluid can be deduced by detecting the resistance of the graphene. Based on this principle, the flow rate of the liquid inside the pipe 2 where the graphene sensing element 4 is located can be further deduced by detecting the resistance of the graphene sensing element.

[0028] A rectangular thin-film graphene sensing element is installed inside the liquid flow pipe 2. Preferably, the graphene sensing element is positioned in the center plane of the liquid flow inside the pipe 2, thereby maximizing the contact between the graphene sensing element and the liquid inside the pipe 2, so that the resistance of the graphene sensing element changes with the flow rate of the liquid inside the pipe 2.

[0029] The graphene sensing element can also be configured as a sleeve structure. When the graphene sensing element is installed in the pipe 2, the liquid in the pipe 2 can pass through the outer surface of the graphene sensing element and simultaneously pass through the through hole in the center of the sleeve, making the interface area between the graphene sensing element and the liquid larger.

[0030] The rectangular thin-film graphene sensing element has the same length direction as the liquid flow direction in pipe 2, which allows the graphene sensing element to fully contact the flowing liquid. The longer contact distance makes the resistance change of the graphene sensing element more obvious. At the same time, during detection, the long contact distance also reduces the instantaneous influence of impurities on the graphene sensing element.

[0031] Flexible carriers 5 are fixed at both ends of the graphene sensing element 4. The flexible carriers 5 are directly sleeved on both ends of the graphene sensing element 4. The flexible carriers 5 wrap around both ends of the graphene sensing element 4. The flexible carriers 5 can fix the graphene sensing element by friction fit, clamping or direct clamping. At the same time, the flexible carriers 5 can also protect the graphene sensing element by wrapping around both ends of the graphene sensing element, preventing the ends of the graphene sensing element from being damaged by the impact of water flow for a long time.

[0032] The flexible carrier 5 is provided with an encapsulation layer 6, which is used to fix the sensor assembly 3 to the pipe 2. The overall shape of the encapsulation layer 6 is not limited. The encapsulation layer 6 is directly connected and fixed to the pipe 2. Both ends of the encapsulation layer 6 are fixedly sleeved on the pipe 2, so that the liquid in the pipe 2 can flow directly through the cavity of the encapsulation layer 6. The encapsulation layer 6 has a cavity, and the shape of the cavity is set to correspond to the pipe 2, so that the liquid in the pipe 2 can flow smoothly through the cavity. Preferably, the inner diameter of the cavity is the same as the inner diameter of the pipe 2, so that the flow rate of the liquid in the pipe 2 does not change when it flows through the encapsulation layer 6.

[0033] Except for the cavity, the encapsulation layer 6 is a solid structure. The encapsulation layer 6 serves to fix the flexible carrier 5. The flexible carrier 5 is attached to the encapsulation layer 6 with adhesive. At the same time, the flexible carrier 5 itself fixes the graphene sensing element 4. Thus, the graphene sensing element 4 is fixed by the encapsulation layer 6, so that the graphene sensing element 4 can directly contact the liquid flowing in the pipe 2.

[0034] The encapsulation layer 6 can be elliptical or cylindrical in shape. It protrudes and connects to the pipe 2, thus not only providing good protection for the graphene sensing element but also directly displaying its installation location for easy maintenance. The encapsulation layer 6 is preferably made of epoxy resin or PDMS. A protective cover 7 can also be fitted over the encapsulation layer 6 to further strengthen the connection between the sensor assembly 3 and the pipe 2, serving as a second, more airtight protective barrier.

[0035] The graphene sensing element has wires 8 at both ends, which are electrically connected to the two ends of the graphene sensing element 4. The wires 8 can be connected to the two ends of the graphene sensing element by soldering or printing circuit. The wires 8 of the graphene sensing element are led out from one end of the encapsulation layer 6 along the water flow direction and are connected to the external circuit. Preferably, the led-out wires 8 are connected to the water meter 1, so that the resistance of the graphene sensing element can be detected in real time, so as to further deduce the flow rate of the liquid in contact with the graphene sensing element, and thus further deduce its flow rate.

[0036] The water meter 1 can integrate related circuits for detecting the resistance change of the graphene sensing element and further converting it into an electrical signal. The water meter 1 is also equipped with a processor, which is equipped with a processing circuit for calculating the flow rate from the electrical signal of the resistance change. At the same time, the processor can also work with the time circuit to calculate the specific flow rate in the pipe 2.

[0037] Wire 8 connects to the resistance detection circuit, which is connected to the analog-to-digital converter (ADC). The ADC is connected to the signal amplifier. The resistance detection circuit can detect the resistance change of the graphene sensing element in real time through wire 8, and convert the resistance change into an electrical signal through the ADC and transmit it to the signal amplifier. The signal amplifier amplifies the electrical signal of the resistance change and transmits it to the processor located in the water meter 1. The processor has a pre-stored processing algorithm for calculating liquid flow based on resistance change, and further calculates the liquid flow rate based on the duration of the flow rate. The water meter 1 directly displays the liquid flow rate.

[0038] A wire connects to a resistance detection circuit, which in turn connects to an analog-to-digital converter (ADC). The ADC is then connected to a signal amplifier. The resistance detection circuit can detect the resistance change of the graphene sensing element in real time via the wire. The ADC converts the resistance change into an electrical signal, which is then transmitted to the signal amplifier. The signal amplifier amplifies the electrical signal of the resistance change and transmits it to a processor located inside the water meter. The processor obtains the liquid flow rate and, based on the duration of the flow rate, further calculates the liquid flow rate. The water meter then directly displays the liquid flow rate.

[0039] In practical applications, it is mainly used in pipes that are filled with flowing liquid for a long time to detect the flow rate of the liquid fully filled in the pipe. The liquid in the pipe can make even and sufficient contact with the graphene sensing element.

[0040] When a graphene flow sensor is installed in a pipe, the graphene sensing element generates corresponding signal changes based on the aforementioned principle as fluid flows through the sensor. These signals are transmitted to an external processing device via wires, where they are processed and analyzed to obtain real-time flow data.

[0041] Graphene flow sensors offer higher sensitivity and are better suited for detecting small flow rates, with a theoretical accuracy of 0.1L. The high wear resistance, corrosion resistance, and stability of graphene material allow the sensor to have a lifespan of over eight years. Furthermore, graphene possesses extremely high chemical stability and biocompatibility; in water meter applications, graphene sensors are typically encapsulated in a protective layer, preventing direct contact with water and thus avoiding water pollution.

[0042] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A flow sensor based on the resistive properties of graphene, characterized in that, The device includes a water meter and a pipe. The water meter is installed on the pipe, and a sensor assembly connected to the pipe is installed on the pipe. The sensor assembly includes an encapsulation layer, within which a graphene sensing element is disposed. Wires extend from both ends of the graphene sensing element, and flexible carriers are sleeved at both ends of the graphene sensing element. The graphene sensing element is fixed within the encapsulation layer by the flexible carriers. The wires are electrically connected to a resistance detection circuit, and the resistance detection circuit is electrically connected to an analog-to-digital converter.

2. The flow sensor based on the resistive properties of graphene according to claim 1, characterized in that, The graphene sensing element is a rectangular thin sheet.

3. A flow sensor based on the resistive properties of graphene according to claim 2, characterized in that, The graphene sensing element is disposed on the central plane of the pipe.

4. A flow sensor based on the resistive properties of graphene according to claim 3, characterized in that, The length direction of the graphene sensing element is the same as the direction of liquid flow in the pipe.

5. A flow sensor based on the resistive properties of graphene according to claim 1, characterized in that, The flexible carrier is fixed at both ends of the graphene sensing element, and the flexible carrier covers both ends of the graphene sensing element.

6. A flow sensor based on the resistive properties of graphene according to claim 5, characterized in that, The flexible carrier and the graphene sensing element are fixed by friction engagement, clamping, or clipping.

7. A flow sensor based on the resistive properties of graphene according to claim 6, characterized in that, The encapsulation layer has a cavity, and the flexible carrier is fixed in the cavity. The shape of the cavity is the same as that of the pipe.

8. A flow sensor based on the resistive properties of graphene according to claim 7, characterized in that, The inner diameter of the cavity is the same as the inner diameter of the pipe.

9. A flow sensor based on the resistive properties of graphene according to claim 8, characterized in that, Except for the cavity, the encapsulation layer is a solid structure.

10. A flow sensor based on the resistive properties of graphene according to claim 1, characterized in that, The water meter is also equipped with a processor.

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