Dielectric measurement device and test method for multiphase dielectric

Abstract

The invention belongs to the technical field of dielectric measurement, and discloses a dielectric measurement device and a test method for a multiphase dielectric medium. The device comprises a generating cavity used for bearing a dielectric medium; the pair of electrode plates is positioned in the generating cavity and the distance between the electrode plates is adjustable; the heating element is used for providing a heat source for the dielectric measuring device; one end of the condenser is installed on the generating cavity, the other end of the condenser is connected with a multi-way valve, and the condenser is used for providing a cold source for the dielectric measuring device; and a vacuum valve, a pressure gauge and a sampling valve are further mounted on the multi-way valve. According to the invention, a pair of electrode plates with an adjustable distance is utilized to adapt to measurement scenes with different dielectric properties and different test precision requirements, and test parameters can be flexibly adjusted; a stable heat source and a stable cold source can be provided through the heating element and the condenser, and the multi-phase measurement requirement is met; the device structure is simplified, the integrated operation of multiphase dielectric measurement is realized, the measurement efficiency and reliability are improved, and the multiphase dielectric can be accurately tested.

Description

Technical Field

[0001] This invention belongs to the field of dielectric measurement technology, and specifically relates to a dielectric measurement device and testing method for multiphase dielectrics. Background Technology

[0002] Dielectric parameters (such as dielectric constant ε) The loss tangent (tanδ) is a core indicator for evaluating the insulation performance and physical properties of dielectric materials. It is widely used in power equipment operation and maintenance (such as transformer oil and SF6 gas status monitoring), chemical process control (such as multiphase fluid reaction monitoring), and new energy material research and development (such as electrolyte phase analysis).

[0003] Existing dielectric measurement techniques are mainly designed around the dielectric properties of a single phase. Common techniques and their shortcomings for multiphase dielectrics are as follows: 1. Resonance method (coaxial resonant cavity / parallel plate resonant cavity) Principle: By utilizing the changes in the resonant frequency (f0) and quality factor (Q) of the resonant cavity after dielectric filling, the permittivity (ε) can be inversely deduced. ) and loss tangent (tanδ).

[0004] To address the drawbacks of multiphase dielectrics: the fixed structure limits phase adaptation; coaxial resonant cavities are mostly used for gas measurements, but when liquids enter, they easily form non-uniform liquid accumulation in the cavity, leading to resonance peak shift and broadening, with measurement errors exceeding 15%; parallel plate resonant cavities are suitable for liquids, but in gas-liquid two-phase systems, bubbles will disrupt the uniformity of the resonance field, making it impossible to stably extract resonance parameters; multiphase switching is costly, requiring changes to the resonant cavity structure (such as adjusting electrode spacing and cavity shape) to adapt to different phases.

[0005] 2. Time Domain Reflectometry (TDR) Principle: The characteristic impedance of the medium is calculated by observing the time-domain waveform of the reflected signal at the end of the transmission line, and then the dielectric constant is obtained.

[0006] Addressing the shortcomings of multiphase dielectrics: Phase interface interference waveform analysis: In multiphase media (such as gas-liquid two-phase), the reflected signal at the phase interface is superimposed on the main reflected signal, resulting in waveform distortion and making it difficult to accurately extract dielectric parameters; the reflected signal of tiny bubbles (diameter <1mm) is easily submerged by noise, making it impossible to identify phase distribution details.

[0007] 3. Capacitor method (parallel plate capacitor / coaxial capacitor) Principle: Based on the capacitance formula, the dielectric constant is directly calculated by the change in capacitance value.

[0008] Addressing the drawbacks of multiphase dielectrics: poor measurement stability; in gas-liquid two-phase media, the random distribution of bubbles can cause capacitance fluctuations, making it impossible to obtain stable measurement results; when liquid media evaporates or gas liquefies, phase changes can cause sudden changes in capacitance, making it difficult to distinguish whether the change is caused by phase change or medium degradation.

[0009] 4. Impedance analysis (impedance analyzer / LCR meter) Principle: The complex impedance of the electrode system is measured, and the dielectric parameters are fitted by an equivalent circuit model (such as an RC parallel model).

[0010] To address the drawbacks of multiphase dielectrics: mismatch between electrode structure and phase state: parallel plate electrodes are suitable for liquids, but have low signal-to-noise ratio for gas signals; coaxial electrodes are suitable for gases, but liquid adhering to the electrode surface will cause electric field distortion, resulting in impedance measurement deviation.

[0011] Existing technologies are not designed for the core characteristics of multiphase media, such as the randomness of the phase interface and the dynamic changes in phase ratio, resulting in insufficient adaptability.

[0012] In practical applications, dielectrics are often in a multiphase dynamic change state: when a power transformer is running, local overheating can cause the insulating oil to decompose and generate bubbles, forming a gas-liquid two-phase mixed medium; in a low-temperature environment, SF6 high-voltage circuit breakers can cause SF6 gas to liquefy and form a gas-liquid coexistence state; in a chemical reactor, the fluid medium may change from a single-phase liquid to a gas-liquid-solid three-phase mixed state due to temperature / pressure fluctuations.

[0013] In multiphase states, the dielectric properties of dielectrics differ fundamentally from those in single-phase states (e.g., interfacial polarization, phase ratio dependence), and their dielectric parameters directly reflect key information such as the dielectric state and mixing uniformity of the medium. Therefore, developing high-precision dielectric measurement devices suitable for multiphase dielectrics (liquid, gas-liquid two-phase, and gaseous) is of great significance for ensuring equipment safety and optimizing process efficiency. Summary of the Invention

[0014] The purpose of this invention is to provide a dielectric measurement device and testing method for multiphase dielectrics, in order to solve the technical problem that existing dielectric measurement technologies are mainly designed around the dielectric properties of single-phase dielectrics and cannot accurately test multiphase dielectrics.

[0015] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a dielectric measurement device for a multiphase dielectric, comprising: The generating cavity is used to carry the dielectric. A pair of electrode plates are located inside the generating cavity and the spacing between them is adjustable; Heating elements are used to provide a heat source for dielectric measurement devices; The condenser is mounted on the generating chamber at one end and connected to a multi-way valve at the other end to provide a cold source for the dielectric measurement device; the multi-way valve is also equipped with a vacuum valve, a pressure gauge and a sample injection valve.

[0016] A further improvement of the present invention is that it also includes a heat-insulating base; the bottom of the generating cavity is mounted on the heat-insulating base; and the heating element is mounted on the heat-insulating base to provide a heat source for the dielectric in the generating cavity.

[0017] A further improvement of the present invention is that the generating cavity is cubic in shape, and at least one side wall is provided with a viewing window.

[0018] A further improvement of the present invention is that: the condenser is installed on the top of the generating chamber; the condenser is a straight-tube condenser; multiple working fluid channels are evenly arranged in the condenser; in the condenser, cooling water flows around the working fluid channels, and the working fluid channels are directly connected to the internal space of the generating chamber.

[0019] A further improvement of the present invention is that: a set of electrodes is installed on each of the opposite sides of the generating cavity through a heat-insulating sleeve; the electrode includes an electrode plate and an electrode rod; the electrode rod is detachably connected to one side of the electrode plate; the electrode rod passes through the side wall of the generating cavity and is provided with a first sealing structure, and passes through the outer end of the heat-insulating sleeve and is provided with a second sealing structure.

[0020] A further improvement of the present invention is that both the first sealing structure and the second sealing structure are sealing rings.

[0021] A further improvement of the present invention is that: the generating cavity is provided with a vertical positioning groove; the positioning groove is used to install a spacing control plate for adjusting the spacing between a pair of electrode plates.

[0022] A further improvement of the present invention is that the external pipeline of the injection valve is connected to a condenser component.

[0023] A further improvement of the present invention is that the generating cavity is made of a non-metallic material.

[0024] A further improvement of the present invention is that the generating chamber and the condenser are connected by a flange-chuck structure.

[0025] Secondly, the present invention provides a dielectric measurement method for a multiphase dielectric, based on the aforementioned dielectric measurement device for a multiphase dielectric, comprising the following steps: Assemble the generating chamber and heating element; A pair of electrode plates are installed in the generating chamber; the pair of electrode plates are adjusted to the set spacing using the spacing control plate; Assemble the condenser, multi-way valve, pressure gauge, vacuum valve and injection valve in sequence to complete the sealing of the dielectric measurement device; Open the vacuum valve to create a negative pressure in the dielectric measurement device, close the vacuum valve and open the injection valve to inject the dielectric to be tested; when testing liquid and gas-liquid two-phase states, the liquid level is above the top of the electrode plate, and when testing gaseous states, the liquid level is below the bottom of the electrode plate. Adjusting the power of the heating element causes the dielectric to undergo a phase change, forming a gas-liquid two-phase state. The gaseous dielectric is then condensed and refluxed through the condenser. Adjust the condenser to match the condensing power with the heating power until the pressure gauge reading stabilizes and the system reaches a steady state; A voltage is applied to the electrode plates to conduct a dielectric test.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a dielectric measurement device for a multiphase dielectric, comprising: a generating chamber for carrying the dielectric; a pair of electrode plates located within the generating chamber with an adjustable spacing; a heating element for providing a heat source for the dielectric measurement device; a condenser, one end of which is mounted on the generating chamber and the other end connected to a multi-way valve for providing a cold source for the dielectric measurement device; the multi-way valve is also equipped with a vacuum valve, a pressure gauge, and a sample injection valve. This invention provides a stable testing environment for multiphase dielectrics by setting up a generating cavity to carry the dielectric. Utilizing a pair of adjustable-pitch electrodes, it can adapt to measurement scenarios with different dielectric properties and varying testing accuracy requirements, flexibly adjusting test parameters. A stable heat source provided by a heating element allows for precise control of the dielectric phase change process, promoting the formation of gas-liquid and other multiphase states to meet the needs of multiphase measurement. A condenser, acting as both a cold and heat source, enables the dielectric phase change cycle. Simultaneously, a multi-port valve integrates a vacuum valve, pressure gauge, and injection valve, giving the device the functions of negative pressure environment construction, real-time pressure monitoring, and precise dielectric injection. This simplifies the device structure, achieves integrated operation for multiphase dielectric measurement, and improves measurement efficiency and reliability. It allows for accurate testing of multiphase dielectrics.

[0027] Furthermore, this invention adds a heat-insulating base and mounts the bottom of the generating chamber onto the heat-insulating base, while integrating the heating element onto the heat-insulating base. On the one hand, the heat-insulating base can effectively prevent the heat of the heating element from dissipating to the outside of the device, reducing energy loss and ensuring that the heat is concentrated on the dielectric inside the generating chamber, thereby improving heating efficiency and temperature control accuracy. On the other hand, the heat-insulating base provides stable mounting support for the generating chamber and the heating element, avoiding safety hazards caused by direct contact between the heating element and the outside, while reducing the interference of the external ambient temperature on the internal temperature field of the chamber, ensuring the stability of the dielectric phase change process, and thus improving the accuracy of dielectric measurement results.

[0028] Furthermore, the generating cavity in this invention adopts a cubic structure, which facilitates the standardized installation and positioning of components such as electrodes and viewing windows, improving the ease of device assembly. By setting a viewing window on at least one side wall, the state changes of the dielectric in the generating cavity can be observed in real time and intuitively, including key information such as phase transition process, phase distribution, and liquid level. This allows operators to promptly determine whether the dielectric has reached the preset test state, avoiding result deviations caused by blind testing. At the same time, it facilitates the timely detection of abnormalities during the testing process, improving the controllability and safety of the testing process.

[0029] Furthermore, this invention installs the condenser at the top of the generating chamber, allowing the gaseous dielectric to rise naturally into the condenser without the need for an additional power unit, thus simplifying the fluid flow path. The condenser adopts a straight-tube structure with multiple working fluid channels evenly arranged, increasing the heat exchange area between the gaseous dielectric and the cooling water and improving condensation efficiency. The design of cooling water flowing around the working fluid channels ensures uniform heat exchange and avoids gaseous dielectric residue caused by insufficient local condensation. The working fluid channels are directly connected to the internal space of the generating chamber, allowing the condensed liquid dielectric to flow directly back into the generating chamber, forming a closed-loop circulation, reducing dielectric loss, and ensuring the stability of the total dielectric volume during testing. This avoids changes in measurement conditions due to dielectric loss and improves the continuity and accuracy of multiphase dielectric measurements.

[0030] Furthermore, this invention uses an insulating sleeve to install the electrodes on opposite sides of the generating chamber. The insulating sleeve effectively reduces heat loss from the electrode rod, preventing deformation or performance fluctuations due to temperature changes and ensuring the stability of electrode signal transmission. The electrodes feature a detachable connection between the electrode sheet and the electrode rod, facilitating electrode sheet replacement, cleaning, and maintenance, and adapting to testing scenarios with different sizes and material requirements. By setting a first sealing structure where the electrode rod passes through the side wall of the generating chamber and a second sealing structure where it passes through the outer end of the insulating sleeve, the double sealing design effectively blocks the exchange of gas and liquid between the inside of the generating chamber and the external environment. This ensures the stability of the negative pressure environment or specific gas atmosphere inside the chamber, prevents safety hazards and environmental pollution caused by dielectric leakage, and avoids external impurities from entering the chamber and affecting the measurement results.

[0031] Furthermore, this invention provides a vertical positioning groove inside the generating cavity, offering a precise installation and positioning reference for the spacing control plate, ensuring its stable position and preventing displacement after installation. By adjusting the spacing between a pair of electrode plates by installing the spacing control plate in the positioning groove, compared to traditional manual adjustment, precise control of the electrode spacing can be achieved. Spacing control plates of different thicknesses can adapt to different spacing requirements, offering convenient operation and high adjustment efficiency. Precise electrode spacing control reduces dielectric constant calculation deviations caused by spacing errors, improving the repeatability and accuracy of measurement results, and providing a reliable basis for comparative experiments under different spacing conditions.

[0032] Furthermore, by connecting the external pipeline of the injection valve to the condensing component, when measuring gaseous dielectrics, the gaseous dielectrics evaporated in the generating chamber can be guided to the external condensing component for condensation and liquefaction, and then returned to the generating chamber through the pipeline, forming a complete liquid replenishment circuit. This design avoids the loss of dielectrics caused by the inability of gaseous dielectrics to condense under the heat preservation state of the condenser, ensuring a constant total amount of dielectric during the test, and preventing the accumulation of gaseous dielectrics in the internal pipeline of the device from affecting pressure stability. In addition, the external condensing component can flexibly select condensation parameters according to test requirements, adapting to the measurement of dielectrics with different boiling points, thus expanding the applicability of the device.

[0033] Furthermore, the cavity in this invention is made of a non-metallic material. Compared to metallic materials, non-metallic materials have excellent insulation properties, which can prevent the cavity itself from forming a conductive circuit or generating stray capacitance, reduce interference with the electric field distribution between electrodes, and ensure the purity of the dielectric measurement signal. At the same time, non-metallic materials generally have good chemical stability and are not prone to reacting with the dielectric being measured, avoiding dielectric contamination and cavity corrosion, and extending the service life of the device. In addition, some non-metallic materials also have thermal insulation properties, which can help reduce heat loss inside the cavity, improve temperature control, and further ensure the accuracy of the measurement results.

[0034] Furthermore, this invention achieves the connection between the generating chamber and the condenser through a flange-to-chuck structure. Compared with traditional threaded connections or welding methods, the flange-to-chuck structure has the advantage of rapid assembly and disassembly, significantly improving the convenience of device maintenance, cleaning, and component replacement. At the same time, the flange-to-chuck structure has reliable sealing performance, effectively ensuring the airtightness and liquid tightness of the connection between the generating chamber and the condenser, avoiding gas leakage or dielectric leakage during testing, and ensuring a stable internal pressure environment and testing safety. In addition, this connection structure is highly versatile, easily adaptable to condensers of different specifications, improving the compatibility and expandability of the device.

[0035] This invention provides a method for measuring the dielectric properties of multiphase dielectrics. Based on the aforementioned device, standardized assembly steps ensure accurate positioning and reliable sealing of all components, providing a stable hardware foundation for measurement. Adjusting the electrode plates to a set spacing using a spacing control plate ensures the accuracy of measurement parameters. Injecting the dielectric under negative pressure removes air from the cavity, preventing interference with the dielectric properties. Simultaneously, precise control of the liquid level height according to different phase testing requirements ensures that testing conditions meet preset requirements. Matching and adjusting the heating and condensation power promotes the dielectric to reach a steady state of boiling and condensation equilibrium. Dielectric testing at this state yields the true dielectric property parameters of the multiphase dielectric under stable conditions. The entire method is logically clear and operationally standardized, effectively reducing human error and improving the accuracy, repeatability, and reliability of measurement results. It is applicable to various dielectric property measurement scenarios for multiphase dielectrics. Attached Figure Description

[0036] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the dielectric measurement device for a multiphase dielectric according to an embodiment of the present invention; Figure 2 for Figure 1 A side view of a dielectric measuring device for a multiphase dielectric is shown. Figure 3 for Figure 1 The image shows a rear view of a dielectric measuring device for a multiphase dielectric. Figure 4 This is a schematic diagram of the generating cavity in a dielectric measurement device for a multiphase dielectric according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the heat-insulating sleeve in a dielectric measurement device for a multiphase dielectric according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the electrode structure in a dielectric measuring device for a multiphase dielectric according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the installation structure of the generating cavity and electrodes in a dielectric measurement device for a multiphase dielectric according to an embodiment of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0038] The following detailed description is exemplary and intended to provide further detailed explanation of the invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this invention is for describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention.

[0039] Please see Figures 1 to 7 As shown, this embodiment of the invention proposes a dielectric measurement device for multiphase dielectrics based on impedance analysis, comprising: a generating chamber 1, a heating element 2, a heat-insulating base 3, an electrode 4, a condenser 5, a vacuum valve 6, a pressure gauge 7, and a sample injection valve 8.

[0040] Please see Figure 1 and Figure 4 As shown, the generating cavity 1 is cubic in shape, and a viewing window 10 is provided on at least one side wall; the viewing window 10 is used for manual observation of the state of the multiphase dielectric in the generating cavity 1.

[0041] In one specific embodiment, the generating cavity 1, which holds the multiphase dielectric, has a square cavity structure. Viewing windows 10 are installed on both the front and rear ends, electrodes 4 are installed on the left and right ends, an insulating base 3 is installed on the lower end, and a condenser 5 is installed on the upper end via a quick-connect connection. The generating cavity 1 is made of epoxy resin, which also provides insulation. The viewing windows 10 are made of silicon dioxide and are used to observe the multiphase movement of the dielectric.

[0042] In one specific embodiment, the quick-connect is a flange-to-chuck structure 50, used for the rapid assembly and disassembly of the generating chamber 1 and the condenser 5; the condenser 5 is the cold source of the measuring device, made of stainless steel, and achieves heat exchange through cooling water, used for condensing gaseous dielectric; above the condenser 5 is a chuck-to-four-way valve 9, which is connected to the condenser 5, vacuum valve 6, pressure gauge 7 and injection valve 8 respectively, used for pressure monitoring, ambient gas extraction, dielectric injection, etc.

[0043] In one specific embodiment, the condenser 5 can be a straight-tube condenser with multiple working fluid channels evenly arranged. The shell side of the condenser 5 is provided with a cooling water inlet 51 and a cooling water outlet 52. Preferably, the cooling water inlet 51 is located below the cooling water outlet 52, opposite to the flow direction of the working fluid in the working fluid channel. In the condenser 5, the cooling water flows around the working fluid channel, and the working fluid heat exchange space and the cavity space are directly connected. For gas-liquid two-phase testing, the liquid level is ensured to be at least 4 cm above the measuring electrode plate, so that the falling dielectric droplets have little interference with the testing process. For gaseous dielectric testing, the falling droplets will have an impact. Considering this situation, the cooling water temperature in the condenser 5 is at or above the boiling temperature of the medium, which plays a "heat preservation" role to prevent the dielectric from liquefying. At the same time, the external pipeline from the injection valve 8 is connected to the actual condensing component, where the gaseous medium condenses. After condensation, it is then connected back to the generating cavity 1 through the working fluid channel to form a replenishment liquid.

[0044] The bottom of the generating chamber 1 is mounted on the heat-insulating base 3. The heat-insulating base 3 is equipped with a heating element 2, which is the heat source of the measuring device and is used to heat the dielectric to cause it to undergo a phase change and form a multiphase state.

[0045] In one specific embodiment, the heat insulation base 3 is machined with threaded holes for fixing the heating element 2; the heat insulation base 3 is made of polytetrafluoroethylene and is used to control the direction of heat transfer.

[0046] The bottom of the heat insulation base 3 is provided with a fixed base plate 30; the fixed base plate 30 is used for positioning and assembling the heat insulation base 3 and the generating cavity 1, and is provided with positioning holes, which can fix the entire measuring device on the test bench or the bottom surface to prevent vibration interference caused by the flow of multiphase dielectric.

[0047] Electrode 4 includes electrode sheet 40 and electrode rod 41; electrode rod 41 is threadedly assembled with one side of electrode sheet 40, and is made of gold-plated brass, used for loading AC voltage and impedance signal transmission.

[0048] Please see Figure 4 and Figure 7 As shown, the generating cavity 1 has a vertical positioning groove 11, which can accommodate a spacing control piece 42. The thickness of one side of the spacing control piece 42 is the same as the width of the positioning groove 11, allowing it to be precisely installed within the positioning groove 11. This embodiment of the invention includes multiple spacing control pieces 42 of different thicknesses. Each spacing control piece 42 has the same thickness when installed on one side of the positioning groove 11, and all can be precisely positioned within the positioning groove 11. Replacing different spacing control pieces 42 can adjust the spacing between the two electrode pieces 40.

[0049] In one specific embodiment, the dielectric measuring device for a multiphase dielectric of the present invention includes two sets of electrodes 4. The two sets of electrodes 4 are installed on the left and right sides of a generating chamber 1 via two insulating sleeves 31. One end of the insulating sleeve 31 is provided with a sleeve fixing flange 310. The insulating sleeve 31 is fixed to the side wall of the generating chamber 1 via the sleeve fixing flange 310. The insulating sleeve 31 is made of epoxy material and can provide insulation for the electrode rod 41. The other end face of the insulating sleeve 31 is machined with a threaded hole, which cooperates with the electrode fixing flange 311 to realize the positioning and sealing of the electrode rod 41, thereby adjusting the spacing of the electrode plates 40. A first sealing ring 101 and a second sealing ring 313 are respectively provided in the through hole 100 on the side wall of the generating chamber 1 and the through hole 312 on the other end face of the insulating sleeve 31. The electrode rod 41 passes through the two sealing rings for sealing and fixing the electrode rod 41.

[0050] This invention provides a dielectric measurement device for multiphase dielectrics. Utilizing the intrinsic characteristics of pool boiling, the system state can be determined solely based on pressure data changes. This allows for dielectric measurements to be performed while ensuring the stability of the multiphase dielectric, effectively eliminating the influence of phase interface randomness and dynamic changes in phase ratios on the test results.

[0051] This invention provides a dielectric measurement device for multiphase dielectrics. Apart from the electrodes, the entire device does not involve other electrical measurement components, which can effectively eliminate signal interference during the measurement process.

[0052] This invention provides a dielectric measurement device for multiphase dielectrics. By adjusting the position of the control plate through the positioning groove at the center of the front and rear inner walls of the generating cavity, the electrode plates are made centrally symmetrical within the generating cavity. The gas-liquid two-phase flow dielectric generated from the heating surface can pass through the electrode gap from the center, making the measurement data repeatable.

[0053] This invention provides a dielectric measurement device for multiphase dielectrics. Based on the characteristics of the dielectric, the electrode gap in the generating cavity can be adjusted accordingly, thus solving the problem of low signal-to-noise ratio of gas signals encountered in flat plate electrode testing.

[0054] This invention provides a dielectric measurement device for multiphase dielectrics, which has a wide range of applications, requires no modification to the structure of the biological cavity, and can test the types of dielectrics in liquid, gas-liquid two-phase, and gaseous states.

[0055] This invention proposes a dielectric measurement method for multiphase dielectrics based on impedance analysis, and a dielectric measurement device for multiphase dielectrics as described above. The specific dielectric measurement method for multiphase dielectrics is as follows: S1. Assemble the fixed base plate 30, heat insulation base 3, heating element 2 and generating chamber 1, and fix them on the workbench through the fixed base plate 30 to fix the position of the dielectric measurement device of the multiphase dielectric and avoid the influence of vibration and other factors on the test. S2. Pass the two electrode rods 41 through the left and right end faces of the generating chamber 1 respectively, fix the electrode plate 40 on the electrode rods 41, and fix the heat insulation sleeve 31 to the end face of the generating chamber 1 through the sleeve fixing flange 310, and initially assemble the electrode 4 and the generating chamber 1. S3. Take a spacing control piece 42 of a set thickness and install it in the positioning groove 11 of the generating cavity 1, ensuring that the spacing control piece 42 is located at the center of the generating cavity 1 and is perpendicular to the bottom of the cavity; S4. Push the electrode plate 40 toward the center of the generating chamber 1 through the electrode rod 41 until the two electrode plates 40 are completely in close contact with the spacing control plate 42. At this time, the electrode spacing is the thickness of the spacing control plate 42. Complete the end face sealing between the electrode 4 and the generating chamber 1 through the electrode fixing flange 311, and pull out the spacing control plate 42. S5. Assemble the condenser 5, four-way valve 9, pressure gauge 7, vacuum valve 6 and sample inlet valve 8 in sequence to complete the sealed assembly of the measuring device; S6. Open vacuum valve 6, adjust the measuring device to negative pressure, close vacuum valve 6 and open injection valve 8, inject an appropriate amount of the dielectric to be measured into the device (for the measurement of liquid and gas-liquid two-phase dielectrics, the dielectric level surface must be above the top of electrode plate 4; for the measurement of gaseous dielectrics, the dielectric level surface must be below the bottom of electrode plate 4). S7. Adjust the heating element 2 to the set power. The liquid dielectric undergoes a phase change on the surface of the heating element 2, forming a gas-liquid two-phase state. Separation occurs at the surface of the dielectric liquid level. The gaseous dielectric enters the condenser 5 and then condenses into a liquid dielectric, returning to the generating chamber 1. S8. Adjust the cooling water flow rate and velocity of condenser 5 to match the condensing power and heating power of the measuring device until the pressure gauge 7 reading stabilizes. Based on the boiling characteristics of the pool, it can be determined that the boiling and condensation of the dielectric are in balance at this time, and the measuring system reaches a steady state. S9. Apply voltage to electrode sheet 40 through two electrode rods 41 to conduct dielectric testing of multiphase dielectric.

[0056] In one specific implementation, to eliminate the interference of stray capacitance in the test results, the specific method is to keep the generating cavity 1 filled with air and use the dielectric constant of air at that ambient temperature as a parameter for test calibration.

[0057] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A dielectric measuring device for a multiphase dielectric, characterized in that, include: The generating cavity (1) is used to carry the dielectric; A pair of electrode plates (40) are located inside the generating cavity (1) and the spacing between them is adjustable; Heating element (2) is used to provide a heat source for the dielectric measuring device; The condenser (5) is installed on the generating chamber (1) at one end and connected to a multi-way valve at the other end to provide a cold source for the dielectric measuring device; the multi-way valve is also equipped with a vacuum valve (6), a pressure gauge (7) and a sample injection valve (8).

2. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, It also includes a heat-insulating base (3); the bottom of the generating chamber (1) is mounted on the heat-insulating base (3); the heating element (2) is mounted on the heat-insulating base (3) to provide a heat source for the dielectric in the generating chamber (1).

3. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The generating cavity (1) is cubic in shape, and at least one side wall is provided with a viewing window (10).

4. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The condenser (5) is installed on the top of the generating chamber (1); the condenser (5) is a straight tube condenser; multiple working fluid channels are evenly arranged in the condenser (5); in the condenser (5), cooling water flows around the working fluid channels, and the working fluid channels are directly connected to the internal space of the generating chamber (1).

5. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, A set of electrodes (4) is installed on each of the opposite sides of the generating chamber (1) through the heat insulation sleeve (31); the electrode (4) includes an electrode plate (40) and an electrode rod (41); the electrode rod (41) is detachably connected to one side of the electrode plate (40); the electrode rod (41) has a first sealing structure at the end through the side wall of the generating chamber (1) and a second sealing structure at the end through the outer side of the heat insulation sleeve (31).

6. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The generating cavity (1) is provided with a vertical positioning groove (11); the positioning groove (11) is used to install a spacing control plate (42) for adjusting the spacing between a pair of electrode plates (40).

7. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The external pipeline of the injection valve (8) is connected to a condenser component.

8. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The generating cavity (1) is made of non-metallic material.

9. The dielectric measurement device for a multiphase dielectric according to claim 1, characterized in that, The generating chamber (1) and the condenser (5) are connected by a flange-chuck structure.

10. A method for measuring the dielectric properties of a multiphase dielectric, characterized in that, A dielectric measurement device based on any one of claims 1-9 of a multiphase dielectric includes the following steps: Assemble the generating chamber (1) and the heating element (2); A pair of electrode plates (40) are installed in the generating cavity (1); the pair of electrode plates (40) are adjusted to the set spacing by means of the spacing control plate (42); Assemble the condenser (5), multi-way valve, pressure gauge (7), vacuum valve (6) and injection valve (8) in sequence to complete the sealing of the dielectric measurement device; Open the vacuum valve (6) to make the dielectric measuring device negative pressure, close the vacuum valve (6) and open the injection valve (8) to inject the dielectric to be tested; when testing liquid and gas-liquid two-phase states, the liquid level is above the top of the electrode plate (40), and when testing gas, the liquid level is below the bottom of the electrode plate (40); Adjust the power of the heating element (2) to make the dielectric phase change into a gas-liquid two-phase state, and the gaseous dielectric is condensed and refluxed through the condenser (5); Adjust the condenser (5) to match the condensing power with the heating power until the pressure gauge (7) reading stabilizes and the system reaches steady state; A voltage is applied to the electrode sheet (40) to conduct a dielectric test.

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