Multi-stage siphon water level sensing device based on friction nanometer generator

Abstract

The invention provides a multi-stage siphon water level sensing device based on a friction nanometer generator, and aims to overcome the defect that an existing TENG water level sensing device is easily interfered by the environment. The device performs graded monitoring on the water level through a multi-stage siphon structure, and the higher the water level is, the more the triggered siphons are, so that the variable electric signal frequency is generated, and the water level height is accurately reflected. The siphon unit is composed of siphons arranged in an array mode, and each siphon is provided with a water inlet pipe, a water outlet pipe and an exhaust pipe. Through arrangement of a siphon starting position, different water level heights correspond to starting of different siphons. The outlet flow of the siphon unit is converged to the water turbine, the water turbine works through the TENG to generate an electric signal, and the frequency is related to the water level height. The device has the advantages of efficient energy collection, self-driving, durability and reliability, and can bring a major breakthrough to the field of water level monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of water level sensors, and in particular to a water level sensor device based on a friction nanogenerator and a multi-stage siphon structure. Background Art

[0002] With climate change, urbanization and increasing land utilization, the frequency, duration and severity of global flood disasters have increased year by year. It is reported that in recent years, floods account for more than half of global natural disasters, which have caused huge security threats and economic losses to human society. It is urgent to propose advanced flood warning methods. Water level height is a hydrological information in the natural environment that is directly related to the occurrence of floods. It can effectively predict the occurrence of flood events with sudden, random and complex characteristics. Existing water level sensors based on the principles of float, capacitance, ultrasound, etc. can be used to detect water level height. They usually use chemical batteries as external energy supply. Chemical batteries have the advantages of wide range of use, small size and high energy density, but their disadvantages such as limited service life, difficult maintenance and easy failure in extreme environments have greatly limited the further development and application of traditional water level sensors. Therefore, the use of new environmental energy harvesting technology and self-driven sensing technology to replace traditional chemical battery technology to achieve water level sensing and early warning has attracted widespread attention from scholars in this field.

[0003] As an environmental energy harvesting technology or self-driven sensing technology, the triboelectric nanogenerator (TENG) has been used in fluid environments to measure the water level in the environment. According to the role and working principle of TENG in the water level sensing device, the existing TENG-based water level sensing devices can be mainly divided into two categories: TENG-powered and TENG-self-driven. In the TENG-powered water level sensing device, TENG plays the role of an energy harvester, which captures the mechanical energy of the fluid to power the external independent water level sensor in the device. At present, there are two main problems with TENG-powered water level sensing devices: First, the external water level sensor makes the integration, miniaturization and maintenance of the system extremely difficult; second, the normal operation of the external water level sensor depends on the energy size and stability of the TENG energy supply side, which is usually affected by the conditions in its working environment. Environmental changes can easily lead to a decrease in the total energy supply and stability of the system. Compared with TENG-powered water level sensing devices, TENG self-driven sensing water level sensing devices have significant advantages in system integration, miniaturization and power generation capabilities because TENG itself plays the role of both a self-driven water level sensor and an energy harvester. However, existing devices of this type usually rely on the principle of a positive correlation between water level height and TENG output voltage to realize the water level sensing function, and the output voltage is easily disturbed by environmental factors such as humidity, resulting in serious problems of insufficient reliability and stability. Therefore, it is urgent to solve this principle problem of traditional TENG self-driven sensing devices. Summary of the invention

[0004] The technical goal to be achieved by the present invention is to solve the problem of insufficient reliability and stability caused by the existing TENG self-driven water level sensor device being easily disturbed by the environment, and propose a multi-stage siphon water level sensor device based on a friction nanogenerator. The device designs a multi-stage siphon and TENG in a mechanical structure. When the water level in the environment increases, the synergistic effect of the two can be used to first trigger the siphon phenomenon step by step to increase the outlet flow of the multi-stage siphon structure, which increases the rotation speed of TENG, and then establishes a positive correlation between the water level height and the TENG electrical signal frequency. Finally, the TENG electrical signal frequency can be used to characterize the water level height in the environment. At the same time, since environmental factors such as humidity will not affect the frequency, stable and reliable real-time measurement of the environmental water level can be achieved.

[0005] The technical patent provided by the present invention is as follows: a multi-stage siphon water level sensing device based on a friction nanogenerator, the structure of which mainly includes: a siphon unit and a sensing unit.

[0006] The siphon unit includes a plurality of siphons of different structural sizes arranged in a horizontal array. Each siphon has a water inlet, a water outlet and a vent, and a siphon start position and a siphon stop position can be set respectively through structural design. The siphon start positions of different siphons are arranged at equal intervals in the height direction, corresponding to the detection of different water level height levels. In addition, the water outlets of all siphons are connected together through a water collector to form a convergence of the outlet flow of the siphon unit. In the water level rising stage, when the water level rises to the siphon start position of any siphon, the independent siphon drainage event of starting the siphon can be automatically triggered. Correspondingly, the continuously rising water level will start the independent siphon drainage events of other siphons one by one. Therefore, the higher the water level, the more siphons start the siphon event, and the greater the outlet flow of the siphon unit. In the water level falling stage, when the water level drops to the siphon stop position of any siphon, the independent siphon drainage event of closing the siphon can be automatically triggered. Correspondingly, the continuously decreasing water level will close the independent siphon drainage events of other siphons one by one. Therefore, the lower the water level, the fewer siphons are needed to maintain the siphon event, and the smaller the outlet flow of the siphon unit. In summary, the outlet flow of the siphon unit corresponds to the number of siphons that open the siphon drainage event, and the number of siphons corresponds to the different height levels of the water level. Therefore, the device can use the outlet flow of the siphon unit to characterize the water level level, and the trend of the outlet flow can be used to characterize the state of water level rise or fall. In addition, the siphon unit can convert the random and disordered fluid potential energy in the environment into stable and orderly fluid kinetic energy through the water storage process and triggering the siphon drainage event. At the same time, when the water level changes within each set water level height level, the output flow of the siphon unit is approximately unchanged, so the rotation speed and output power of the TENG in the sensing unit can be maintained relatively constant, so the device can also be used as an energy conversion device with stable output energy.

[0007] The sensing unit includes a turbine, a shaft, two flange couplings, a TENG, a support and a base frame. One side of the turbine impeller is located directly below the outlet of the siphon unit. The turbine is connected to the TENG through a shaft and a flange coupling. The TENG works based on an independent layer mode, including a rotor, a stator, a copper foil, and a fluorinated ethylene propylene (FEP) membrane. The FEP membrane on the outer surface of the rotor serves as a friction layer of the TENG, and the copper foil on the stator serves as another friction layer and an electrode layer of the TENG. The rotor is coaxially connected to the turbine. When the impeller is impacted by the water flow at the outlet of the siphon unit, a rotational motion is generated, thereby driving the TENG to work through the shaft. When the outlet flow of the siphon unit increases, the speed of the turbine increases, causing the frequency of the output electrical signal of the coaxial TENG connected to it to increase. According to the established relationship between the water level height and the outlet flow of the siphon unit, the relationship between the water level height and the frequency of the TENG electrical signal can be established, thereby forming the water level sensing principle of the proposed device, that is, the water level height and the state of water level rise or fall in the environment can be characterized by analyzing the frequency characteristics of the TENG.

[0008] In addition, the sensing unit also has a power generation function. When a siphon event occurs in the siphon unit, its outlet flow will drive the turbine to rotate and convert fluid energy into mechanical energy, thereby driving the TENG to work and convert mechanical energy into electrical energy. According to the established relationship between the water level and the outlet flow of the siphon unit, when the water level changes within each set water level level, the output flow of the siphon unit remains approximately unchanged, so the rotation speed and output power of the TENG in the sensing unit can be maintained relatively constant. Therefore, the device can also be used as an energy conversion device with stable output energy, which can convert the disordered, fluctuating and high-entropy fluid potential energy in the environment into orderly, stable and low-entropy electrical energy, which is conducive to improving the energy conversion efficiency of the device.

[0009] The present invention is based on the sensing principle of TENG frequency characteristics to characterize water level changes, which can achieve real-time and stable detection of water level height, and can recycle fluid energy in the environment. Compared with the prior art, the present invention has the following advantages: 1. In terms of sensing, compared with the traditional sensing principle based on TENG voltage to characterize water level height, the present invention has the core advantages of high resolution, strong resistance to humidity interference, and good stability. At the same time, no external power supply is required, and self-driven sensing detection of water level information can be fully realized; 2. In terms of energy capture, compared with traditional fluid power generation devices, the present invention can convert random, disordered and high-entropy fluid energy in the environment into stable, ordered and low-entropy electrical energy, which can significantly improve the energy conversion efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall structure of a multi-stage siphon water level sensor device based on a friction nanogenerator of the present invention;

[0011] Figure 2 This is one of the structural schematic diagrams of a siphon unit in a multi-stage siphon water level sensor device based on a friction nanogenerator according to the present invention;

[0012] Figure 3 This is the second structural schematic diagram of the siphon unit in the multi-stage siphon water level sensor device based on the friction nanogenerator of the present invention;

[0013] Figure 4 It is a structural schematic diagram of a sensing unit in a multi-stage siphon water level sensing device based on a friction nanogenerator of the present invention;

[0014] Figure 5 This is a schematic diagram of the structure of TENG in a multi-stage siphon water level sensing device based on a friction nanogenerator of the present invention;

[0015] Figure 6 It is the siphon principle of a multi-stage siphon water level sensor device based on a friction nanogenerator of the present invention;

[0016] Figure 7 This is the working principle of TENG in a multi-stage siphon water level sensor device based on a friction nanogenerator of the present invention;

[0017] Figure 8 The present invention discloses a detection method for a multi-stage siphon water level sensor device based on a friction nanogenerator;

[0018] In the figure: 1. siphon unit; 2. sensor unit; 11. siphon unit container 12. siphon pipe 13. connector 14. water collector 15. siphon unit water outlet; 121. water outlet 121. water inlet 123. vent 124. siphon start position 125. siphon stop position 21. sensor unit base; 22. turbine; 23. flange; 24. TENG 25. shaft; 241. stator 242. copper foil 243. FEP film 244. rotor. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments 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 creative work are within the scope of protection of the present invention.

[0020] The following is combined with Figure 1-8 The present invention is described in further detail.

[0021] The embodiment of the present invention discloses a multi-stage siphon water level sensor device based on a friction nanogenerator and a detection method thereof. Figure 1 A multi-stage siphon water level sensing device based on a friction nanogenerator comprises a siphon unit (1) and a sensing unit (2). The siphon unit (1) is installed directly above the sensing unit (2).

[0022] Reference Figure 2 The siphon unit (1) is provided with a siphon unit container (11) facing the environmental water level height detection, and a plurality of multi-stage siphon tubes (12) of different structural sizes, wherein the multi-stage siphon tubes (12) are arranged in the form of a horizontal array, and the inner bottom of the siphon unit (1) is also provided with a water collector (14) for collecting the outlet flow of the multi-stage siphon tubes (12), wherein the water collector (14) and the multi-stage siphon tubes (12) are connected by a threaded fastener (13), and the water outlet (15) of the siphon unit is arranged at the outer bottom of the siphon unit (1) for discharging the flow collected in the water collector (14).

[0023] Refer to the attached Figure 3 Each siphon tube in the multi-stage siphon tube (12) is provided with a water outlet (121), a water inlet (122) and a vent (123); the top position of the siphon tube can be used to set a siphon start position (124) for starting an independent siphon drainage event of the siphon tube; the water inlet (122) is used to connect the siphon tube with the siphon unit container (11); and the end position of the vent (123) can be used to set a siphon stop position (125) for closing an independent siphon drainage event of the siphon tube.

[0024] Refer to the attached Figure 4 The sensing unit (2) is composed of a sensing unit bracket (21), a water turbine (22), a flange (23), a TENG (24), and a shaft (25); the water turbine (22) and the TENG (24) are coaxially connected to the sensing unit bracket (21), and two flanges (23) respectively fix the water turbine (22), the TENG (24) and the shaft (25). It should be noted that the outermost impeller part of the water turbine (22) is directly below the water outlet (15) of the siphon unit (1), and this design is conducive to utilizing the fluid kinetic energy at the outlet of the siphon unit; the stator of the TENG (24) and the sensing unit bracket (21) are fixed with threaded fasteners.

[0025] Refer to the attached Figure 5The TENG comprises a stator (241), a copper foil (242), a FEP film (243) and a rotor (244). The FEP film (243) is in a rectangular paddle shape with a certain curvature and is evenly spaced on the outer wall of the rotor; the copper foil (242) is evenly spaced on the inner wall of the stator. The stator (241) and the rotor (244) are coaxially distributed, and the FEP film is completely in contact with the surface of the copper foil during installation.

[0026] Refer to the attached Figure 6 , taking the array distribution of five siphon tubes in the siphon unit as an example, the siphon principle of the device is explained. Assuming that the water level rises, when the water level reaches the siphon start position (124) of the first-stage siphon tube, the siphon drainage event of the first-stage siphon tube will be triggered and started. Therefore, the output flow generated by the first-stage siphon tube will become the outlet flow Q of the siphon unit (Q=Q1). If the water level continues to rise and reaches the height of the siphon start position of the second-stage siphon tube, the first-stage and second-stage siphon tubes will simultaneously undergo siphoning, and the water outlet flow of the siphon unit is equal to the sum of the outlet flows of the two siphon tubes (Q=Q1+Q2). Obviously, when the water level rises to the height of the siphon start position of the Nth siphon tube, the total water outlet flow of the siphon unit is Q: (Q=Q1+Q2+...+Q N ). Similarly, assuming that the water level drops, the outlet flow of the siphon unit will decrease step by step according to the same rule as above. Therefore, according to the working principle of the siphon unit, the relationship between the water level in the environment and the water flow of the siphon unit is established. Then, the fluid energy in the siphon process is converted into the corresponding TENG electrical signal frequency through the sensing unit, so the relationship between the water level and the electrical signal frequency is established for real-time detection of the water level.

[0027] Refer to the attached Figure 7, explaining the working principle of TENG in the device. When the device of the invention is located in a water environment and the water level is higher than the siphon start position of the siphon tube (11), a siphon drainage event is triggered, and the stored water in the container is discharged outward through the outlet through the siphon drainage event, forming stable fluid mechanical energy. At this time, the water flow impacts the turbine (22) to drive the rotor (244) on the shaft (25) to rotate, so that the FEP film (243) on the rotor (244) and the copper foil (242) inside the stator (241) rub to transfer charge. The FEP film (243) begins to contact the copper electrode 1. At this time, the FEP film (243) has a negative charge due to its inherent charge characteristics, while the copper electrode 1 has a positive charge. This charge configuration establishes an initial electrostatic field in the system. As the FEP film begins to slide under the push of the water flow, it moves toward the second electrode (copper electrode 2). In this process, the FEP film (243) slides from the positive charge area of ​​the copper electrode 1 to the copper electrode 2. The copper electrode 2 initially maintains a charge separation state with the copper electrode 1, that is, the copper electrode 2 is negatively charged. Due to the movement of the FEP film, the electrostatic balance previously established with the copper electrode 1 is broken, resulting in a significant potential difference between the two electrodes. This potential difference causes the current to flow from the copper electrode 1 to the copper electrode 2, realizing the dynamic conversion of energy. When the FEP film (243) continues to move and finally completely overlaps with the copper electrode 2, the charge in the system is redistributed again to reach a new electrostatic equilibrium state. At this position, the charges of the copper electrode 1 and the copper electrode 2 are effectively transferred and rebalanced through the FEP film. In the process of the FEP film (243) continuing to move, separating from the copper electrode 2 and starting to return to the copper electrode 1, the electrostatic equilibrium state is once again destroyed. This rapid charge change and movement generates an induced current, which is a direct product of the energy conversion process. It provides a way for the device to convert fluid mechanical energy into electrical energy.

[0028] Refer to the attached Figure 8 , a detection method for a multi-stage siphon water level sensing device based on a friction nanogenerator. According to the above principle, when the water level in the environment changes, the change in the siphon unit outlet flow rate will eventually be reflected in the change in the TENG electrical signal frequency. In this figure, taking the water level rising process as an example, as the siphon drainage event of each level of the siphon in the siphon unit is triggered and started, the frequency of TENG also increases. In this embodiment, the minimum frequency of TENG is 6.25 Hz when the first-level siphon is working, and the maximum frequency of TENG is 19.01 Hz when the fifth-level siphon is working. Therefore, the water level height level can be reflected according to the TENG electrical signal frequency, realizing real-time detection of the environmental water level.

[0029] In summary, the present invention proposes a multi-stage siphon water level sensing device based on a friction nanogenerator, which can utilize the siphon effect principle and the TENG self-driven sensing principle to cooperate with each other to realize the sensing detection of the environmental water level height and changes. At the same time, it can convert fluid energy into electrical energy to power other low-power sensors.

Claims

1. A multi-stage siphon water level sensing device based on a friction nanogenerator, comprising a siphon unit (1) and a sensing unit (2).

2. The siphon unit (1) includes a plurality of siphon tubes of different structural sizes arranged in a horizontal array. Each siphon tube has a water inlet, a water outlet and a vent, and a siphon start position and a siphon stop position can be set respectively through structural design. The siphon start positions of different siphon tubes are arranged at equal intervals in the height direction, corresponding to the detection of different water level height levels.

3. The sensing unit (2) also has a power generation function. When a siphon event occurs in the siphon unit (1), its outlet flow will drive the turbine to rotate and convert fluid energy into mechanical energy, thereby driving the TENG to work and convert mechanical energy into electrical energy.

Images