Method for producing electrical energy by a direct piezoelectric effect from pressure fluctuation caused by an electrical hydraulic shock in a fluid

Abstract

The invention relates to the field of electrical engineering, and more particularly to methods for producing electrical energy using transducer elements, and can be used for producing electrical energy. A method for producing electrical energy using a direct piezoelectric effect consists in creating an electrical hydraulic shock within a volume of fluid and a fluctuation in pressure inside a confined space, resulting in a mechanical action on a piezoelectric element and the subsequent production of electrical energy by a direct piezoelectric effect. The technical result of the invention consists in an increase in the generation of electrical energy, which is produced through the use of an electrical hydraulic shock.

Description

[0001] A method for generating electrical energy by direct piezoelectric effect from pressure changes in a liquid by electrohydraulic shock

[0002] The invention relates to the field of electrical engineering, namely, concerns methods for obtaining electrical energy using converting elements, and can be used to obtain electrical energy by creating short-term electrical pulse discharges in a liquid, the result of which are electrohydraulic shocks, during which shock pressure occurs within the volume of liquid, and the conversion of the obtained mechanical energy into electrical energy using at least one piezoelectric element.

[0003] A known art method for converting energy using a frequency-controlled piezoelectric energy harvester for hydraulic cylinders (CN112953299 A, IPC F15B 21 / 14, H02N 2 / 18, published 06 / 11 / 2021) comprises a hydraulic cylinder, a housing, a piezoelectric guide sleeve, a piezo piston, a piezoelectric battery unit, a Glia ring and a manual throttle, a valve core, sealing rings, throttle valve seats, elastic pre-tightening linings, piezoelectric pre-tightening nuts, etc.; the housing and the hydraulic cylinder are connected by welding, it includes a throttle valve cavity and a piezoelectric component cavity, a drain hole channel, an oil port cavity; Among them, there is a cavity of the throttle valve, the cavity of the throttle valve is a cavity of the piezoelectric component along the circumference, and the cavity of the throttle valve communicates with the cavity of the piezoelectric component through the channel of the drainage hole.The piezoelectric pre-tensioning device is also housed within the piezoelectric component cavity. The end of the throttle valve cavity is provided with internal threads for mounting the throttle valve seat; the end of the piezoelectric component cavity is provided with internal threads for mounting the piezoelectric pre-tensioning nut; the end of the bleed port channel is provided with internal threads for installing the bleed port plug.

[0004] The method utilizes piezoelectric energy harvesting technology in a conventional hydraulic cylinder to recover hydraulic shock energy in a hydraulic system. This method converts pressure energy into electrical energy, which is then collected and used to actuate electromagnetic valves and sensors in a hydraulic system with low-power components. Due to the hydraulic shock generated by the flow of fluid in the hydraulic cylinder, particularly the high impact pressure generated within the cylinder when the piston retracts, the piezoelectric component is easily deformed under the excitation of this pressure, thereby generating electrical energy. In the prior art solution, a piezoelectric material package is embedded within the hydraulic cylinder.

[0005] The disadvantages of the known analogue include low efficiency and effectiveness, the inability to achieve high and ultra-high pressures, and the inability to generate increased amounts of electrical energy. The known method only produces enough electrical energy to operate the solenoid valves and sensors in a hydraulic system with low-power components.

[0006] Also known from the prior art is a method according to which a piezoelectric element is placed inside a pipeline (housing), collecting piezoelectric energy from pulsations (oscillations) of hydraulic pressure present in a hydraulic or other liquid system subject to pumping action, using a system (US10211761 B2, IPC H02N 2 / 18, HO 1L 41 / 113, published 02 / 19 / 2019), which contains: 2 a housing made in the form of an annular space; a piezoelectric unit communicating through a fluid medium with.pressure pulsations of a liquid system and configured to generate a piezoelectric voltage and an associated piezoelectric current in response to the characteristics of the pressure pulsations, wherein the piezoelectric package is located inside the housing, and wherein the piezoelectric package contains an axially polarized piezoelectric layer; a control circuit electrically connected to the piezoelectric unit and configured to convert the piezoelectric current into a direct current voltage.

[0007] The disadvantages of the known system also include low efficiency with low effectiveness, the inability to obtain high and ultra-high pressures with the creation of the possibility of generating an increased amount of electrical energy using a piezoelectric element.

[0008] As indicated in the description of the prior art, in various embodiments, the known method and the system used to implement it can be used in liquid systems (i.e., pumped liquid systems). For example, the known method can be used in water and / or oil pipelines to power sensors that monitor the pipelines. Furthermore, in various embodiments, it can be used in hydraulic components such as pumps, actuators, and valves. Using the known method and the system used to implement the method, it is possible to power sensors used in conjunction with such components.In addition, in various embodiments, it can be used in components of the pumped liquid (for example, to provide power to sensors used in conjunction with such components), or in combination with pressurized lubrication systems (for example, lubrication systems in internal combustion engines, turbine engines, or steam engines). The closest analogue chosen is a method for generating electrical energy using a piezoelectric transducer (RU Patent 209 171 U1, IPC H02N 2 / 18, published 04.02.2022, Bulletin No. 4), in which a mechanical effect is transmitted to a pressure measuring device built into a sealed housing through the liquid onto the surface of the piezoelectric elements, on the plates of which a potential difference arises due to mechanical deformation.A piezohydraulic electric current generator contains a transducer connected in parallel to a resistor, a rectifier, a storage capacitor, and an output control electronic circuit. To amplify power, individual piezoelectric elements are combined into sections compactly housed in a sealed housing with a built-in pressure-regulating device. This device applies mechanical force, which is amplified and transmitted through the fluid to the transducers.

[0009] The choice of pressure-changing device type depends on the available source of mechanical action. A membrane is used for a vibrating source. If a rotating source of mechanical action is present, a piston with a crank mechanism is used, creating the alternating (pulsating) action necessary to generate charges in the piezoelectric element.

[0010] The following should be noted as disadvantages of the closest analogue.

[0011] The known method and the device used to implement it are unable to generate high or ultra-high pressures, thereby generating increased amounts of electrical energy. Furthermore, the known method does not provide the ability to generate a highly effective, amplified mechanical pulse for multidirectional action on a piezoelectric element or elements. Furthermore, according to the known method, the mechanical source is designed and mounted above the container to provide unidirectional mechanical action (in one direction) on the piezoelectric elements, which are positioned below the mechanical source. This prevents multidirectional action and increases the area of ​​mechanical action on the piezoelectric element, thereby reducing the effectiveness and efficiency of the known method and device.

[0012] The invention is based on the task of creating a new, highly efficient method for generating electrical energy through a direct piezoelectric effect from a change in pressure by an electrohydraulic shock in a liquid.

[0013] The stated objective is achieved in that in the method for obtaining electrical energy by direct piezoelectric effect from a change in pressure by an electrohydraulic shock in a liquid, in which a mechanical action is exerted on at least one piezoelectric element with a change in pressure in the liquid in a limited space with subsequent obtaining of electrical energy from the direct piezoelectric effect, according to the proposal, the change in pressure is reproduced by implementing an electrohydraulic shock inside the volume of the liquid.

[0014] In this case, according to the proposal, the electrohydraulic shock is carried out by producing a pulsed electrical discharge in a volume of liquid in such a way that the pressure increases.

[0015] In this case, according to the proposal, an increase in pressure is ensured with the implementation of an electrohydraulic shock both with an increase in the amount of energy released during the discharge and with an increase in the steepness of the pulse front (energy discharge rate), with a change in the distance between the electrodes and the characteristics of the liquid itself.

[0016] In this case, according to the proposal, the volume of liquid is limited by a round wall, which is made as at least one piezoelectric element.

[0017] According to the proposal, the liquid volume is limited by an open or closed container with a spherical wall containing at least one piezoelectric element. Furthermore, according to the proposal, additional piezoelectric elements are placed in the liquid between the electrodes and the container walls to optimally absorb the mechanical energy from the electrohydraulic shock.

[0018] In this case, according to the proposal, the container is completely filled with liquid, and the liquid is provided with a pressure that is optimal for the effective transfer of pressure from the center of the container to the walls of the container.

[0019] The listed features of the proposed technical solution are essential features of the claimed invention, and their combination makes it possible to obtain the expected technical result - ensuring the creation of high and ultra-high shock pressure by electrohydraulic impact within a volume of liquid with a multidirectional effect on at least one piezoelectric element, which makes it possible to generate electrical energy.

[0020] The cause-and-effect relationship between the essential features of the proposed solution and the achieved technical result is as follows.

[0021] The claimed set of essential features ensures an increase in productivity with an increase in the amount of electrical energy obtained from the piezoelectric element or piezoelectric elements using the claimed method by a direct piezoelectric effect, efficiency, since with the creation of electrohydraulic shocks with the reproduction of electrical pulse discharges in the volume of liquid, it is possible to obtain high and ultra-high pressures, a consistent pulse from an electrohydraulic shock with the receipt of a significantly enhanced mechanical effect on at least one piezoelectric element.

[0022] The further essence of the invention is explained in the description given below as a non-limiting embodiment of the claimed method, with reference to the drawings, which show: Fig. 1 - a schematic representation of an embodiment of a circuit of interconnected elements for creating an electric hydraulic shock, R - charging resistance;

[0023] Tr - Transformer;

[0024] V - Rectifier;

[0025] Ts - forming spark gap;

[0026] Sg - Electrohydraulic hammer; Fig. 2 - top view of a variant of a container filled with liquid for carrying out an electrohydraulic hammer with an impact on a piezoelectric element, where:

[0027] P - the wall of the container in the form of a piezoelectric element made of piezoelectric material;

[0028] -E- is the symbol for the liquid that fills the container;

[0029] Ei - impulse from electric hydraulic shock;

[0030] Sg - Electrohydraulic hammer.

[0031] The claimed method, in an embodiment that does not limit other possible embodiments, is performed as follows.

[0032] To achieve a mechanical effect on at least one piezoelectric element, the pressure is changed by performing an electrohydraulic shock inside a volume of liquid in a limited space, followed by obtaining electrical energy from the direct piezoelectric effect.

[0033] In this case, electrohydraulic shock is achieved by a short-term pulsed electrical discharge in a liquid, causing the pressure to increase. The following factors influence the resulting pressure around the electrical discharge:

[0034] - the amount of energy released during discharge;

[0035] - steepness of the pulse front (rate of energy release);

[0036] - the distance between the electrodes in the liquid; the physical properties of the liquid in which the electrohydraulic shock occurs. Liquid 5, in which the electrohydraulic shock is produced, is placed in container 1, the walls 2 of which and the piezoelectric elements, which are placed in liquid 5, are preliminarily shaped to provide the optimal shock wave absorption.

[0037] The volume of liquid 5 in the embodiment is limited by an open or closed container (optimally spherical in shape), which is at least one piezoelectric element.

[0038] In the center of a pre-made container 1 made from a piezoelectric element, one pair or cascade of several successively arranged pairs of electrodes 3 are placed, designed with the possibility of optimally implementing an electrohydraulic shock by reproducing a pulsed electrical discharge.

[0039] In one embodiment, a container 1 with a spherical wall 2 is formed as a piezoelectric element (piezoelectric) capable of collecting piezoelectric energy generated by mechanical action on wall 2. Wall 2, as well as, in one embodiment, the lower wall (bottom of container 1) and / or the upper wall (lid of container 1), may be formed as a single piezoelectric element or comprise a plurality of piezoelectric elements. Electrodes 3 are installed in the central portion of container 1 and connected to an electrical circuit that generates a pulse with a steep front. Pairs of electrodes 3 may be installed sequentially across the entire height of container 1.

[0040] Container 1 is filled with liquid 5.

[0041] An electric hydraulic shock Sg is produced in a volume of liquid 5 located in a container 1.

[0042] An electric hydraulic shock generates an ultra-high pressure impulse Ei, as well as other effects: thermal energy, chemical reactions, acoustic impulses.

[0043] Due to the incompressibility (the negligible small compressibility coefficient for liquids) of liquid 5, this impulse Ei, with minimal losses, spreads throughout the entire liquid 5 in all directions from the epicenter of the electrohydraulic hammer.

[0044] The change in pressure reaches the piezoelectric element or elements, the surface or surfaces of which, wall 2 or walls 2 (in the embodiment of the container 2 with several walls 2 made at an angle relative to one another) touch the liquid 5, and they are affected by mechanical energy, which leads to the generation of electrical energy through a direct piezoelectric effect.

[0045] The generated electrical energy is collected through any known circuit electrically connected to a piezoelectric element acting as wall 2.

[0046] The claimed method allows for the generation of electrical energy using an electro-hydraulic shock, which results in a sharp, strong change in pressure in a liquid medium, from which electrical energy is generated through the direct piezoelectric effect.

[0047] "The direct piezoelectric effect is the phenomenon of the generation of electrical polarity in a crystalline material when a mechanical stress is applied." [Fundamentals of Piezoelectricity by Takashi Ikeda, 2010, 1 page]

[0048] A sudden change in pressure on a piezoelectric material can generate a piezoelectric voltage. Piezoelectric materials respond to mechanical deformation, and a change in pressure in a liquid is one form of such deformation.

[0049] "Pascal's principle: a change in pressure applied to a confined fluid is transmitted invariably to all parts of the fluid and to the walls of the container." ["Fluid Mechanics" by Frank M. White 2015, page 17] This means that when pressure arises in one part of a liquid, the pressure spreads to the entire liquid at approximately the speed of sound. This principle follows from the fact that all liquids have an extremely small compression ratio (for example, for water K = 0.0000512). "The electro-hydraulic effect is a new industrial method of converting electrical energy into mechanical energy with a high efficiency." [Book by L.A. Yutkin "The Electro-Hydraulic Effect and Its Application in Industry" 1986, page 6] The electro-hydraulic effect was studied and used mainly to create the highest possible pressure in the "destruction zone" or "riveting zone" (Figure 1). The remaining zones were of no interest to scientists and were considered side effects.But I believe that the study and application of the effects of electric-hydraulic shock on the walls of a container will bring greater results in the development of this little-studied technology.

[0050] Fig. 3 and the definition of zones are taken from the book by L.A. Yutkin “Electrohydraulic effect” 1955. [Books by L.A. Yutkin “Electrohydraulic effect” 1955. And page]. Fig. 3:

[0051] A - "Spark charge zone" is the zone where the discharge breakdown occurs.

[0052] B - "The destruction zone" is where maximum pressure occurs. This zone is currently used to the maximum extent in the application of electric-hydraulic impact for crushing and grinding hard and especially hard materials, possibly to dispersed particles. As L.A. Yudin points out in his book, in this zone "the liquid briefly acquires the state of a solid elastic body."

[0053] B- “Riveting zone” is a zone with lower pressure than in the “destruction zone”, but is also used for the destruction and crushing of solid materials and riveting of metals.^

[0054] G - "Elastic impact zone" - particles are ejected and a powerful pushing action occurs.

[0055] D - "Compression zone" pressure decreases very quickly with increasing distance from the spark discharge.

[0056] By applying many formulas for calculating the generation of electrical energy in this way, it was concluded that by exposing a liquid to an effective discharge (the optimal amount of energy for the minimum amount of time at the optimal distance between the electrodes, taking into account the physical properties of the liquid), it is possible to obtain a short-term, localized, strong increase in pressure in the liquid, disproportionate to the energy expended. And if liquid 5 is placed in a closed container 1, which is 100% filled with only liquid 5 under increased pressure, and an electrohydraulic hammer occurs in this liquid 5, then, taking into account Pascal's principle, this high local pressure (taking into account losses) will effectively spread to the walls of container 1.

[0057] Understanding this effect, if the walls of container 1 are made of non-diffusion (undeformed) or predictably deformed (diffusion) piezoelectric elements, and to optimally increase the area of ​​pressure action on the piezoelectric elements, 5 piezoelectric elements are placed inside container 1 in a liquid. These piezoelectric elements will not be located in the zone of the electro-hydraulic shock discharge channel structure (the zone where there is extremely high pressure, cavitation, active thermal, chemical, and other reactions). It will turn out that electricity, with the help of electro-hydraulic shock, is converted into high-pressure mechanical energy, which, through the liquid, with minimal losses, transfers pressure to the walls of the piezoelectric element. This energy is converted into electrical energy via the direct piezoelectric effect.

[0058] Taking into account the low efficiency of the conversion of mechanical energy (in our case, water pressure) into electrical energy through the direct piezoelectric effect, but in a container 1, for example, in the form of a sphere, it is possible to place many layers of piezoelectric material (with technical holes for transmitting a shock wave sequentially to other layers) which will interact with the pressure of liquid 5, so that the area of ​​action of the pressure of liquid 5 on the piezoelectric material is as productive as possible (for example, in the form of a ball (most similar to the shape of a blast wave)).A comparative analysis of the above technical solution with the closest analogue showed that the implementation of the set of essential features characterizing the proposed invention leads to the emergence of qualitatively new technical properties indicated above, the set of which was not previously established from the existing level of technology, which allows us to conclude that the proposed technical solution meets the criterion of “inventive step”.

[0059] In the existing sources of patent and scientific-technical information, no method for obtaining electrical energy by direct piezoelectric effect from pressure changes in liquid by electrohydraulic shock has been found that has the stated set of essential features; therefore, the presented technical solution meets the criterion of "novelty."

[0060] In addition, the proposed method for generating electrical energy through a direct piezoelectric effect from a change in pressure via an electrohydraulic shock in a liquid is suitable for industrial application, since it does not require the use of any technological processes, structural elements or materials that could not be reproduced at the current stage of development of science and technology, and therefore this technical solution is considered to meet the criterion of "industrial applicability".

Claims

FORMULA 1. A method for obtaining electrical energy by a direct piezoelectric effect from a change in pressure by an electrohydraulic impact in a liquid, in which a mechanical action is exerted on at least one piezoelectric element with a change in pressure in the liquid in a limited space, followed by obtaining electrical energy from a direct piezoelectric effect, which is characterized in that the change in pressure is reproduced by implementing an electrohydraulic impact inside the volume of the liquid.

2. The method according to paragraph 1, which is characterized in that the electrohydraulic shock is carried out by producing a pulsed electrical discharge in a volume of liquid in such a way that the pressure increases.

3. The method according to paragraph 1, which is characterized in that it provides an increase in pressure with the implementation of an electrohydraulic shock both with an increase in the amount of energy released during the discharge and with an increase in the steepness of the pulse front (energy discharge rate), with a change in the distance between the electrodes and the characteristics of the liquid itself.

4. The method according to paragraph 1, which is characterized in that the volume of liquid is limited by a round wall, which is made as at least one piezoelectric element.

5. The method according to paragraph 1, which is characterized in that the volume of liquid is limited by an open or closed container with a spherical wall, which is at least one piezoelectric element.

6. The method according to paragraph 1, which is characterized in that piezoelectric elements are also placed in the liquid between the electrodes and the walls of the container for optimal absorption of mechanical energy from the electrohydraulic shock. 13 The method according to paragraph 1, which is characterized in that the container is completely filled with liquid, and the liquid is provided with a pressure that is optimal for the effective transfer of pressure from the center of the container to the walls of the container.

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