Oil non-uniform distribution water content detection device based on microwave resonance technology

Abstract

The utility model belongs to pipeline oil product water content detection equipment technical field relates to a kind of oil product non-uniform distribution water content detection device based on microwave resonance technology.Detection device, including microwave transmitting device, MCU, antenna, pipeline, detection device and microwave transmission line;Microwave transmitting device passes through MCU control D / A converter to the different voltage signals of VCO input, produce different frequency microwave signal, microwave signal is input antenna again through microwave transmission line;Whole antenna can be attached to pipeline;Detection device's logarithmic detector converts the microwave signal power of antenna output into voltage signal, MCU receives voltage signal and is passed into PC through serial port, PC can then data analysis processing, and the water content of oil product in pipeline is obtained by characteristic frequency.This device antenna is small in size, easy to install, and can accurately detect the water content of oil products.

Description

Technical Field

[0001] This utility model belongs to the technical field of oil water content detection equipment in pipelines, specifically relating to a detection device for non-uniformly distributed water content in oil based on microwave resonance technology. Background Technology

[0002] Water content in refined oil products has various negative impacts on their performance and use, depending on the type and intended application. Taking lubricating oil as an example, water can disrupt the integrity of the oil film, reducing lubrication and increasing friction and wear on mechanical parts, thus affecting equipment lifespan. It can also cause oil oxidation and deterioration. When water mixes with oil, it can form emulsions, altering viscosity and reducing fluidity, thus impacting transportation and usage. Measuring the water content in refined oil products is crucial for ensuring quality, preventing performance issues caused by excessive water, maintaining normal equipment operation, and ensuring safe production. Similarly, for diesel and gasoline, water reduces combustion efficiency, leading to insufficient engine power. For transformer oil, water significantly reduces insulation properties, potentially causing short circuits or arcing. Controlling water content is particularly important in the production, storage, transportation, and use of critical oil products such as lubricating oil, fuel oil, and transformer oil.

[0003] Currently, existing methods for detecting water content in oil products include distillation, capacitance, and ultrasonic methods, all of which have certain limitations. For example, distillation is based on the difference in boiling points between water and oil at different temperatures. It involves heating the oil in a closed system to gradually vaporize the water, then collecting the vaporized water to measure the water content. However, this method requires manual sampling, leading to significant randomness, and each sampling and measurement session is time-consuming, failing to meet the requirements for rapid online detection. The capacitance method detects solution concentration based on the property that changes in the dielectric constant of the solution within a capacitor affect its capacitance value, but this method has low accuracy. The ultrasonic method measures the acoustic parameters of different liquids by analyzing the propagation characteristics of ultrasound in a liquid medium, thereby measuring liquid concentration. However, this method involves complex detection parameters and cumbersome data processing.

[0004] Microwave methods have many advantages, such as the ability to measure the water content of oil in real time, non-contact measurement to avoid the possibility of sample contamination, and strong penetration ability to penetrate non-metallic substances to measure the sample.

[0005] Meanwhile, the distribution of moisture in oil products exhibits two states: uniform distribution and non-uniform distribution. Currently, there are many measurement techniques and research reports on uniform distribution. However, there is less discussion and research on non-uniform moisture distribution. Based on practical conditions, non-uniform moisture distribution in oil products is quite common, especially when the water content is high. The non-uniformity of moisture in oil products will be more obvious, and may even lead to stratification. Due to the difference in water and oil density, the lower half of the layer will contain more water than the upper half.

[0006] Therefore, it is essential to develop a microwave-based device for detecting non-uniform water content in oil products. This device can not only detect the non-uniform distribution of water content in oil products, but also assess oil quality and ensure safe storage and transportation. It also has significant practical implications for improving the production efficiency and economic benefits of the oil industry, and its application prospects are broad. Summary of the Invention

[0007] The purpose of this invention is to provide a device for detecting the non-uniform distribution of moisture in oil based on microwave antenna technology, so as to solve the problems of slow detection speed, low detection accuracy and complicated installation of existing equipment.

[0008] This utility model is achieved through the following technical solution:

[0009] A device for detecting non-uniform water content in oil based on microwave resonance technology includes a microwave transmitting device 1, an MCU 2, an antenna, a pipeline 5, a detection device 6, and a microwave transmission line 7.

[0010] The microwave transmitting device 1 consists of a D / A converter 8 and a VCO 9. The D / A converter 8 is controlled by an MCU 2 to input different voltage signals to the VCO 9. The MCU 2 and the D / A converter 8 are connected through a digital interface bus. The MCU 2 transmits the control signals of the D / A converter 8 to the D / A converter 8 and provides a stable power supply and reference voltage to the D / A converter 8. The VCO 9 generates microwave signals of different frequencies, and then inputs the microwave signals to the antenna through the microwave transmission line 7.

[0011] The antenna, including an upper antenna 3 and a lower antenna 4, is composed of an antenna metal patch 10, an antenna dielectric substrate 11, an antenna ground plane 12, an antenna transmitting port 13, and an antenna receiving port 14. The entire antenna can be attached to the pipe 5. When the antenna transmitting port 13 is excited, a radio frequency electromagnetic field is excited between the antenna metal patch 10 and the antenna ground plane 12, which radiates outward through the gap between the antenna dielectric substrate 11 and the surrounding antenna ground planes 12. During the measurement process, the upper antenna 3 and the lower antenna 4 can be measured simultaneously. The antenna transmitting ports 13 of the upper antenna 3 and the lower antenna 4 are connected to VCO 9, and the antenna receiving ports 14 are connected to the logarithmic detector 15.

[0012] The detection device 6 consists of a logarithmic detector 15, a serial port 16, and a PC 17. The logarithmic detector 15 receives the microwave signal output from the antenna receiving port 14 through the microwave transmission line 7. The logarithmic detector 15 converts the power of the microwave signal output from the antenna into a voltage signal. The MCU2 receives the voltage signal and transmits it to the PC 17 through the serial port 16. The PC 17 can then analyze and process the data to obtain and display the water content of the oil in the pipeline 5.

[0013] Furthermore, the microwave transmitting device 1 is connected to the microwave transmission line 7 to input the microwave signal into the antenna transmitting port 13. The microwave transmission line is connected to the antenna transmitting port through an SMA adapter, and the signal is fed back by the antenna receiving port 14 and then transmitted to the logarithmic detector 15 by the microwave transmission line 7.

[0014] Furthermore, the microwave transmitting device 1 transmits microwave signals to the antenna. The microwave signals act on the internal space of the pipe 5. When the wavelength of the input high-frequency electromagnetic wave matches the relative permittivity of the oil in the pipe, the S-parameter curve will produce obvious characteristic peaks or valleys. The corresponding characteristic frequency f can be used as a detection parameter, indicating that the antenna system has a resonance phenomenon at this frequency. The characteristic frequency of the antenna will also be different for oils with different water contents. The higher the water content of the oil, the higher its permittivity and the lower the corresponding characteristic frequency of the antenna.

[0015] Furthermore, the pipe 5 is made of non-metallic material with a dielectric constant comparable to that of pure oil, and the outer wall radius of the pipe ranges from 35 to 45 mm, while the wall thickness ranges from 1 to 3 mm.

[0016] Furthermore, the antenna has a size of 50×50mm to 70×70mm, the dielectric substrate is made of non-metallic material, and the dielectric loss tangent is less than 0.002.

[0017] Furthermore, the dielectric substrate is a flexible material that is easy to bend; or a rigid material that has a curvature that matches the measuring pipe.

[0018] Furthermore, there are two antennas, one located directly above the pipe and the other directly below the pipe. They are symmetrically distributed and have the same structure, sharing the same microwave transmitting and detection device, and are used to measure the water content of the upper and lower regions of the pipe, respectively.

[0019] Furthermore, the measurement results of the upper antenna 3 and the lower antenna 4 theoretically have the same weight. By averaging the measurement results of the upper and lower antennas, a more accurate and corrected moisture content measurement result can be obtained.

[0020] Compared with the prior art, the beneficial effects of this utility model are:

[0021] This utility model is an oil non-uniform water content detection device based on microwave technology. The antenna is small and easy to install. The entire measuring equipment is simple and lightweight to install, which can solve the problems of excessive size and complicated installation and disassembly of existing detection equipment. It is also low in cost. This utility model can accurately detect the water content of oil and can perform real-time online, non-contact measurement of non-uniform water content (uneven water content in the upper and lower parts) in pipelines. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the non-uniform moisture content measuring device of this utility model;

[0024] Figure 2 A schematic diagram of the antenna structure;

[0025] Figure 3 Front view of the device for detecting water content in oil products;

[0026] Figure 4 Side view of the device for detecting water content in oil products;

[0027] Figure 5 Top view of the device for detecting water content in oil products;

[0028] Figure 6 Structural block diagram of the device system of this utility model;

[0029] Figure 7 Simulation curve of the upper antenna when the oil in the pipeline has a uniform water content;

[0030] Figure 8 Simulation curve of the lower antenna when the oil in the pipeline has a uniform water content;

[0031] Figure 9 Simulation curve of the upper antenna when the oil in the pipeline contains uneven water content;

[0032] Figure 10 Simulation curve of the lower antenna when the oil in the pipeline contains uneven water content;

[0033] Figure 11 The curves showing the relationship between the resonant frequencies of the upper and lower antennas and the water content when the oil in the pipeline has a uniform water content, and the curves showing the relationship between the average resonant frequency obtained from the upper and lower antennas and the water content;

[0034] Figure 12 The curves showing the relationship between the resonant frequencies of the upper and lower antennas and the water content of oil in a pipeline with non-uniform water content, and the curves showing the relationship between the average resonant frequency obtained from the upper and lower antennas and the water content;

[0035] Figure 13 The curves showing the relationship between the average resonant frequency of the antenna and the water content are presented for oil in pipelines with uniform and non-uniform water content.

[0036] In the diagram: 1. Microwave transmitter 2. MCU 3. Upper antenna 4. Lower antenna 5. Pipe 6. Detection device 7. Microwave transmission line 8. D / A converter 9. VCO 10. Antenna metal patch 11. Antenna dielectric substrate 12. Antenna ground plane 13. Antenna transmitting port 14. Antenna receiving port 15. Logarithmic detector 16. Serial port 17. PC. Detailed Implementation

[0037] The present invention will be further described below with reference to embodiments:

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0039] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this utility model, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0040] like Figure 1 , Figure 6 As shown, the oil non-uniform water content distribution detection device based on microwave resonance technology of this utility model mainly consists of a microwave transmitting device 1, a single-chip microcomputer or microcontroller (MCU) 2, an upper antenna 3, a lower antenna 4, a pipe 5, a detection device 6, a microwave transmission line 7, a D / A converter 8, a voltage-controlled oscillator (VCO) 9, an antenna metal patch 10, an antenna dielectric substrate 11, an antenna ground plane 12, an antenna transmitting port 13, an antenna receiving port 14, a logarithmic detector 15, a serial port 16, and a host computer (PC) 17.

[0041] The upper antenna 3 is attached to the pipe 5. The microwave transmitting device 1 is connected to the microwave transmission line 7. The microwave transmitting device 1 inputs the high-frequency signal to the antenna transmitting port 13 through the microwave transmission line 7, and then the signal is fed back to the detection device 6 through the antenna receiving port 14 via the microwave transmission line 7. The lower antenna 4 is connected in the same way.

[0042] During this process, VCO9 outputs microwave sweep signals of different frequencies to measure the frequency response of the S-parameters. The power of the microwave signal is converted into voltage in the logarithmic detector 15, and the signal power transmitted from the antenna transmit port 13 to the antenna receive port 14 is measured, outputting a voltage proportional to the signal power. The output voltage of the logarithmic detector 15 at each frequency point is acquired and converted into the amplitude of the S-parameters. The horizontal axis of the S-parameters corresponds to the output frequency range of VCO9, showing the change of the S-parameters with the antenna's characteristic frequency; the vertical axis represents the amplitude of the S-parameters, indicating the attenuation or gain of the signal transmitted from the antenna transmit port 13 to the antenna receive port 14. The S-parameter curve obtained by frequency sweeping will have extreme points (characteristic peaks or valleys). The corresponding characteristic frequency f (resonant frequency) can be used as a detection parameter, indicating that the antenna system has a resonance phenomenon at that frequency. Under normal temperature conditions, the relative permittivity of water is as high as about 80, while that of typical oils, such as lubricating oil, is only about 2.3. The difference in dielectric properties means that even a slight change in the water content of the oil will cause a change in the overall dielectric constant of the mixture. For oils with different water contents, the characteristic frequency of the antenna will also be different. The higher the water content of the oil, the higher its dielectric constant, and the lower the corresponding characteristic frequency of the antenna.

[0043] The microwave transmitting device 1 consists of a D / A converter 8 and a VCO 9. An MCU 2 controls the D / A converter 8 to input different voltage signals to the VCO 9, thereby generating microwave signals of different frequencies. These microwave signals are then input to the antenna via a microwave transmission line 7. The MCU 2 and the D / A converter 8 are connected via a digital interface bus, such as SPI or I2C. 2 The MCU2 is connected via a C-protocol bus. It transmits control signals from the MCU2 to the D / A converter 8. Simultaneously, it provides a stable power supply and reference voltage to the D / A converter 8.

[0044] MCU2 receives the voltage signal and transmits it to PC17 via serial port 16. PC17 can then analyze and process the data to obtain and display the water content of the oil in pipeline 5.

[0045] The microwave transmitting device 1 is connected to the microwave transmission line 7, inputting microwave signals into the antenna transmitting port 13. The microwave transmission line is connected to the antenna transmitting port via an SMA adapter, and the signal is fed back from the antenna receiving port 14, then transmitted to the logarithmic detector 15 via the microwave transmission line 7. Specifically, the microwave transmitting device 1 emits high-frequency electromagnetic waves, which enter the antenna transmitting port 13 through the microwave transmission line 7. The high-frequency electromagnetic waves act on a portion of the space inside the pipe 5. When the wavelength of the input high-frequency electromagnetic waves matches the relative permittivity of the oil in the pipe 5, the S-parameter curve will produce obvious characteristic peaks (valleys), at which point the energy stored in the antenna reaches its maximum. The detection device 6 consists of the logarithmic detector 15, a serial port 16, and a PC 17. The antenna receiving port 14 transmits the high-frequency electromagnetic waves to the detection device 6 via the microwave transmission line 7, and the logarithmic detector 15 detects and outputs the signal. The logarithmic detector 15 receives the microwave signal output from the antenna receiving port 14 via the microwave transmission line 7, and converts the power of the microwave signal output by the antenna into a voltage signal. At this time, MCU2 receives the voltage signal, and the obtained parameters are processed by MCU2 and can be transmitted to PC17 through serial port 16. PC17 can then analyze and process the data, and the water content of the oil in pipeline 5 can be calculated from the parameters displayed by PC17.

[0046] like Figure 2 As shown, the upper antenna 3 includes an antenna metal patch 10, an antenna dielectric substrate 11, an antenna ground plane 12, an antenna transmit port 13, and an antenna receive port 14. The lower antenna 4 is similar.

[0047] like Figure 3 , Figure 4 , Figure 5 The upper antenna 3 and lower antenna 4 shown have a certain curvature, i.e., a certain arc, or the dielectric substrate material has a certain elasticity, and can be attached to the pipe 5, dividing the interior of the pipe 5 into two regions, with the center line as the boundary, containing oil in the upper and lower regions respectively. The upper antenna 3 and lower antenna 4 detect the water content of the oil in the upper and lower regions respectively. When the antenna transmitting port 13 is excited, a radio frequency electromagnetic field is excited between the antenna metal patch 10 and the antenna ground plane 12, which radiates outward through the gap between the antenna dielectric substrate 11 and the surrounding antenna ground planes 12. During the measurement process, the upper antenna 3 and lower antenna 4 can be measured simultaneously. The antenna transmitting port 13 of the upper antenna 3 and lower antenna 4 is connected to VCO 9, and the antenna receiving port 14 is connected to the logarithmic detector 15.

[0048] The microwave transmitting device 1 and the detection device 6 can be replaced by a vector network analyzer (VNA). The VNA transmits microwave signals with known frequency and phase. After passing through the test pipe 5, the VNA can compare the incident wave and the transmitted wave to detect the S-parameter curve of the antenna system.

[0049] The circular pipe 5 is made of non-metallic material with a dielectric constant comparable to that of pure oil. The outer radius of the pipe 5 ranges from 35 to 45 mm, and the wall thickness ranges from 1 to 3 mm.

[0050] The antenna dimensions range from 50×50mm to 70×70mm. The dielectric substrate is made of non-metallic material with a dielectric loss tangent of less than 0.002, such as the RT 5880 laminate. The material has a relative permittivity of 2.2, a dielectric loss tangent of 0.0009, and a thickness of 1 to 2mm. The dielectric substrate is a flexible material that is easy to bend; or a rigid material that has a curvature that matches the measuring conduit 5.

[0051] There are two antennas, one directly above pipe 5 and one directly below pipe 5, symmetrically distributed and identical in structure, sharing the same microwave transmitting device 1 and detection device 6. They are used to measure the water content in the upper and lower regions of pipe 5, respectively. Due to the relatively limited microwave operating space of the antennas and the inability to cover the entire cross-section of pipe 5, the antennas need to be positioned at the upper and lower parts of pipe 5 to measure the medium characteristics in different regions. The upper antenna 3 acts on the medium in the upper space of pipe 5, and the measured parameters mainly reflect the water content in the upper space region. Similarly, the lower antenna 4 mainly reflects the water content in the lower space region.

[0052] In this invention, since the upper and lower structures of pipe 5 are symmetrical, the measurement results of the upper antenna 3 and the lower antenna 4 theoretically have the same weight. Therefore, a more accurate and corrected moisture content measurement result can be obtained by averaging the measurement results of the upper antenna 3 and the lower antenna 4. This processing method can effectively reduce local measurement errors and improve the overall measurement accuracy and reliability.

[0053] The S-parameter response curve of the antenna system was simulated and solved using the finite element simulation software HFSS. Figure 7 The simulation curves of the water content of the oil in the upper part of the pipeline 5 detected by the upper antenna 3 when the water content of the oil in the pipeline 5 is uniform are 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%. Figure 8 The simulation curves of the water content of the oil in the lower half of the pipeline 5, detected by the lower antenna 4, are 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10% when the water content of the oil in the pipeline 5 is uniform.

[0054] like Figure 7 and Figure 8 As shown, Figure 7 The characteristic curve corresponding to the upper antenna 3 is S12, the extreme point of the amplitude of the S-parameter curve, and the corresponding characteristic frequency is f. Figure 8The characteristic curve corresponding to the lower antenna 4 is S12 (lower), the extreme point of the S-parameter curve amplitude, and the corresponding characteristic frequency is f (lower). The average resonant frequency is [value missing]. The resonant frequency of the antenna is related to the dielectric constant of the oil in pipe 5. Oils containing different amounts of water have different dielectric constants. The higher the water content, the larger the dielectric constant of the oil, and the smaller the corresponding antenna resonant frequency. The water content of the oil can be reflected by the resonant frequencies of the upper antenna 3 and the lower antenna 4.

[0055] In a non-uniform model, the average moisture content *b*, the moisture content of the upper and lower parts relative to the average moisture content *δ*, and the moisture content of each part are *b* ± *δ*, respectively. Taking *δ* = 1% as an example... Figure 9 To simulate the water content of oil in the upper part of pipeline 5 when the water content of the upper and lower parts deviates from the average water content by 1%, the simulation curves of nine samples with water content of 1% to 9% in the upper part of pipeline 5 detected by the upper antenna 3 are obtained, with an interval of 1%. Figure 10 To simulate the water content of oil in the lower half of pipeline 5 when the water content of the upper and lower parts deviates from the average water content by 1%, the simulation curves of nine samples with a water content of 1% to 9% in the lower half of pipeline 5 detected by the lower antenna 4 are obtained.

[0056] like Figure 12 The figure shows the relationship between the antenna resonant frequency and the water content when the oil has a non-uniform water content. Points with a water content of b actually represent an average water content of b. The corresponding water content in the upper region measured by the upper antenna 3 is b1 = b - 1%, and the corresponding water content in the lower region measured by the lower antenna 4 is b2 = b + 1%. Figure 12 The resonant frequency curves of the upper antenna 3 and the lower antenna 4 are shown in the figure.

[0057] To demonstrate the effectiveness of the device's measurement, an ideal homogeneous oil sample model and a stratified oil sample model were constructed and compared when their average water content was the same. The stratified model divides the space of pipe 5 into two uniform regions, with water contents b1 and b2 respectively. In most cases, due to the difference in oil-water density and gravity, the water content in the lower region is greater than that in the upper region, resulting in an actual water content of b1 / b2 for the entire pipe 5. In this case, the water content of the stratified oil sample model is essentially equivalent to that of the homogeneous oil sample model. For cases where the water content of the oil is uniformly distributed, the ideal homogeneous oil sample model can be used, and a single antenna is sufficient for measurement because the water content distribution within pipe 5 is uniform and consistent, leading to identical measurement results from both antennas. For cases where the water content is not uniformly distributed, a simplified two-layer stratified model is used for ease of analysis. Since the oil distribution differs between the upper and lower sections within pipe 5, a single antenna measurement would result in significant error. Therefore, this measuring device employs a dual-antenna measurement system. The upper antenna 3 and lower antenna 4 primarily measure the water content in the upper and lower regions of pipe 5, respectively. The final results are compared with the homogeneous model to verify the measurement effectiveness.

[0058] Specifically, to demonstrate the effectiveness of the device's measurements, an ideal homogeneous oil sample model and a stratified oil sample model were constructed, and compared when their average water content was the same. The stratified model divides the pipeline space into upper and lower regions, with water contents b1 and b2 respectively. The actual water content of the entire pipeline is... At this point, the water content of the oil sample stratification model is actually equivalent to that of a homogeneous oil sample model with a water content of b, measured using a dual-antenna system. The non-homogeneous model has an average water content of b, and the water content of the upper and lower parts is deviated from the average water content by δ, with the water content of the upper part being b±δ respectively. The water content of the upper part is b1=b-δ, corresponding to the antenna resonant frequency f. up The water content of the lower part is b2 = b + δ, corresponding to the antenna resonant frequency f. down Average resonant frequency This non-uniform model is compared with a uniform model with an average water content of b. The antenna resonant frequency f corresponds to the water content in the upper part of the uniform model. 上 The lower part contains water, corresponding to the antenna resonant frequency f. 下 Average resonant frequency Final comparison f avg with f 平 The consistency between the two methods was verified, demonstrating that this method can accurately measure the moisture content in any (uniform and non-uniform) distribution state.

[0059] When using the detection device 6 for non-uniform water content distribution in oil based on microwave resonance technology of this utility model to detect non-uniform water content in oil.

[0060] First, oil (with zero water content) is introduced into pipeline 5 for testing. The S-parameter curve is obtained by measuring with PC17, and then the corresponding characteristic frequency f is obtained. Then, oil with different water contents is added for testing, and the corresponding frequency is obtained by measuring with PC17.

[0061] Taking antenna 3 as an example, the antenna configuration is as follows: the circular pipe 5 is made of polyethylene with a relative permittivity of 2.25, the outer radius of the pipe 5 is 35mm, the pipe wall thickness is 1mm, the upper antenna 3 has a size of 70×70mm, the antenna dielectric substrate 11 is made of RT5880 laminate with a thickness of 2mm, and the lower antenna 4 is the same.

[0062] Using oils with a purity higher than 99.9% as the calibration value, the resonant frequency of the sample detected at this point is fa(…). Figure 7 Middle curve a), f below ( Figure 8 Curve a); According to simulation experiments, the detection accuracy of the resonant antenna is 1%, meaning that for every 1% change in the water content of the oil, its frequency changes by approximately Δf = 30MHz. For example... Figure 11As shown, the three lines basically overlap, indicating that the properties are consistent throughout the uniform water distribution system, i.e., the uniform model system, and the measurements of single antenna and dual antenna are basically the same.

[0063] To measure the water content of oils with non-uniform moisture distribution, oils with different water contents were prepared for testing.

[0064] Nine samples were prepared to achieve an average water content of 1% to 9% in the oil in pipe 5, with one sample prepared at 1% intervals. The water content of the upper and lower parts of pipe 5 was prepared with a deviation of 1% from the average water content. The water content of the upper part of the oil was 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 8%, respectively. The water content of the lower part of the oil in pipe 5 was 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%, respectively.

[0065] These nine samples are added to pipe 5 respectively. The resonant frequency of each sample can be read via PC17. The upper antenna 3 corresponds to the resonant frequency, and the lower antenna 4 corresponds to the resonant frequency. The average resonant frequency is calculated according to the formula. The average resonant frequency detected by the upper antenna 3 and the lower antenna 4 when the water content is uniform is compared with the average value to check the accuracy of the device in detecting non-uniform water content in oil. Figure 12 As shown, for oil products with non-uniform water content, the three lines are parallel but do not coincide, indicating that a single antenna can reflect the regional water content. However, any single antenna measurement deviates significantly from the actual average water content, making it impossible to obtain the overall true water content. Figure 13 As shown, the weighted correction results from the dual-antenna measurements essentially coincide with the uniform moisture content measurement curve, indicating that this method can accurately measure moisture content in any (uniform and non-uniform) distribution. The above experimental results are as follows... Figure 12 , Figure 13 As shown in the figure, this utility model discloses a detection device and system for non-uniform water content in oil based on microwave technology, which can accurately measure the uniform and non-uniform water content in oil.

[0066] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A device for detecting non-uniformly distributed water in oil products based on microwave resonance technology, characterized in that it comprises: It includes a microwave transmitting device (1), an MCU (2), an antenna, a pipe (5), a detection device (6), and a microwave transmission line (7); The microwave transmitting device (1) consists of a D / A converter (8) and a VCO (9). The MCU (2) controls the D / A converter (8) to input different voltage signals to the VCO (9). The MCU (2) and the D / A converter (8) are connected through a digital interface bus. The MCU (2) transmits the control signals of the D / A converter (8) to the D / A converter (8) and provides a stable power supply and reference voltage for the D / A converter (8). The VCO (9) generates microwave signals of different frequencies and then inputs the microwave signals to the antenna through the microwave transmission line (7). The antenna, including an upper antenna (3) and a lower antenna (4), is composed of an antenna metal patch (10), an antenna dielectric substrate (11), an antenna ground plane (12), an antenna transmitting port (13), and an antenna receiving port (14). The entire antenna can be attached to the pipe (5). When the antenna transmitting port (13) is excited, a radio frequency electromagnetic field is excited between the antenna metal patch (10) and the antenna ground plane (12), which radiates outward through the gap between the antenna dielectric substrate (11) and the surrounding antenna ground planes (12). During the measurement process, the upper antenna (3) and the lower antenna (4) can be measured simultaneously. The antenna transmitting ports (13) of the upper antenna (3) and the lower antenna (4) are connected to the VCO (9), and the antenna receiving ports (14) are connected to the logarithmic detector (15). The detection device (6) consists of a logarithmic detector (15), a serial port (16), and a PC (17). The logarithmic detector (15) receives the microwave signal output from the antenna receiving port (14) through the microwave transmission line (7). The logarithmic detector (15) converts the power of the microwave signal output from the antenna into a voltage signal. The MCU (2) receives the voltage signal and transmits it to the PC (17) through the serial port (16). The PC (17) can analyze and process the data to obtain and display the water content of the oil in the pipeline (5).

2. The device for detecting non-uniformly distributed water in oil products based on microwave resonance technology according to claim 1, characterized in that: The microwave transmitting device (1) is connected to the microwave transmission line (7) to input the microwave signal into the antenna transmitting port (13). The microwave transmission line is connected to the antenna transmitting port through the SMA adapter. The signal is fed back by the antenna receiving port (14) and then transmitted to the logarithmic detector (15) by the microwave transmission line (7).

3. The device for detecting non-uniformly distributed water content in oil based on microwave resonance technology according to claim 1, characterized in that: The microwave transmitting device (1) transmits microwave signals to the antenna. The microwave signals act on the space inside the pipe (5). When the wavelength of the input high-frequency electromagnetic wave matches the relative permittivity of the oil in the pipe, the S-parameter curve will produce obvious characteristic peaks or valleys. The corresponding characteristic frequency f can be used as a detection parameter, indicating that the antenna system has a resonance phenomenon at this frequency. The characteristic frequency of the antenna will also be different for oils with different water content. The oil with higher water content has a higher permittivity and a lower corresponding characteristic frequency.

4. The device for detecting non-uniformly distributed water in oil products based on microwave resonance technology according to claim 1, characterized in that: The pipe (5) is made of non-metallic material with a dielectric constant comparable to that of pure oil. The outer wall radius of the pipe ranges from 35 to 45 mm, and the wall thickness ranges from 1 to 3 mm.

5. The device for detecting non-uniformly distributed water in oil products based on microwave resonance technology according to claim 1, characterized in that: The antenna has dimensions ranging from 50×50mm to 70×70mm, and the dielectric substrate is made of non-metallic material with a dielectric loss tangent of less than 0.

002.

6. The device for detecting non-uniformly distributed water in oil products based on microwave resonance technology according to claim 5, characterized in that: The dielectric substrate is made of a flexible material that is easy to bend; or a rigid material that has a curvature that matches the measuring pipe.

7. The device for detecting non-uniformly distributed water in oil products based on microwave resonance technology according to claim 1, characterized in that: There are two antennas, one located directly above the pipe and the other directly below the pipe. They are symmetrically distributed and have the same structure, sharing the same microwave transmitting and detection device, and are used to measure the water content of the upper and lower regions of the pipe, respectively.

8. The device for detecting non-uniformly distributed water content in oil based on microwave resonance technology according to claim 1, characterized in that: The measurement results of the upper antenna (3) and the lower antenna (4) have theoretically the same weight, and the measurement results of the upper and lower antennas are averaged.

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