CN113466312A - Electrolyte solution concentration measuring system and method based on microwave silk screen sensor - Google Patents
Electrolyte solution concentration measuring system and method based on microwave silk screen sensor Download PDFInfo
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- CN113466312A CN113466312A CN202110668398.6A CN202110668398A CN113466312A CN 113466312 A CN113466312 A CN 113466312A CN 202110668398 A CN202110668398 A CN 202110668398A CN 113466312 A CN113466312 A CN 113466312A
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- 239000008151 electrolyte solution Substances 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 12
- 238000005259 measurement Methods 0.000 claims abstract description 48
- 239000002184 metal Substances 0.000 claims abstract description 14
- 238000012545 processing Methods 0.000 claims abstract description 9
- 239000000243 solution Substances 0.000 claims description 24
- 239000003792 electrolyte Substances 0.000 claims description 4
- 239000011159 matrix material Substances 0.000 claims description 4
- 238000000691 measurement method Methods 0.000 claims description 3
- 230000003068 static effect Effects 0.000 claims description 3
- 230000008054 signal transmission Effects 0.000 claims description 2
- 239000012456 homogeneous solution Substances 0.000 claims 1
- 239000010410 layer Substances 0.000 description 9
- 238000005070 sampling Methods 0.000 description 6
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 5
- 239000004327 boric acid Substances 0.000 description 5
- 238000001514 detection method Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000003071 parasitic effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 230000001960 triggered effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/4166—Systems measuring a particular property of an electrolyte
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Abstract
The invention discloses an electrolyte solution measuring system based on a microwave silk screen sensor, which comprises: a measurement channel; the wire mesh sensor is vertically arranged between two layers of metal wires to form a grid structure, wherein one layer of metal wires is an emitter, the other layer of electrode wires is a receiver, and the emitter and the receiver are mutually insulated; a signal transmitting device; the data acquisition equipment is a current detector and outputs a current signal of the combination of the emitter and the receiver to a computer processing system; and the computer processing system is used for processing the acquired signals to obtain concentration values. In addition, the invention also discloses a measuring method for measuring the electrolyte solution by adopting the electrolyte solution measuring system. The invention can realize the advantages of simultaneously meeting the requirements of extremely small interference on flow field flow, real-time on-line measurement, high time and space resolution, extremely high measurement frequency, two-dimensional concentration field measurement, relatively accurate precision, short time required by measurement and the like.
Description
Technical Field
The invention belongs to the technical field of measurement, and particularly relates to an electrolyte solution concentration measurement system and method based on a microwave silk screen sensor.
Background
In the field of concentration measurement of fluid mixing, how to obtain the concentration information of a mixed solution in real time on line is a difficulty. The concentration measurement in the field usually adopts the form of a sampling tube, the sampling tube is designed to extend into a flow channel, and the concentration measurement by a chemical method is carried out after a fluid sample is obtained.
However, it should be noted that the disadvantages are: the on-line detection cannot be realized, namely, the flowing working medium needs to be taken out, and the method is not suitable for the flowing under harsh flowing conditions; the detection frequency is low, and a certain amount of samples are needed in the chemical detection method, so that a certain sampling time is needed, and the detection effect on the working condition with severe flow change is poor; the flow is greatly influenced, and the flow state is greatly influenced due to the arrangement of the sampling tube, so that the predicted flow state cannot be correctly reduced; the measurement position is single, generally, only a single position can be measured in one flow area, and concentration information with higher dimension cannot be obtained.
Based on the above, it is desirable to obtain a new method for measuring the concentration of an electrolyte solution, which can achieve the advantages of minimal interference on flow field flow, real-time online measurement, high time-space resolution, extremely high measurement frequency, two-dimensional concentration field measurement, relatively accurate precision, short measurement time, and the like. Meanwhile, the sensor has better measuring capability for the position (such as the cross section at the pipeline junction and in the flow direction) where the traditional sensor is not suitable for measurement.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides the electrolyte solution measuring system based on the microwave silk screen sensor and the electrolyte solution measuring system based on the microwave silk screen sensor, and the electrolyte solution measuring system can realize the advantages of extremely small interference on flow field flow, real-time online measurement, high time-space resolution, extremely high measuring frequency, two-dimensional concentration field measurement, relatively accurate precision, short measuring time and the like. Meanwhile, the sensor has better measuring capability for the position (such as the cross section at the pipeline junction and in the flow direction) where the traditional sensor is not suitable for measurement.
In order to achieve the above object, the present invention is achieved by the following aspects:
in a first aspect, the present invention provides an electrolyte solution measurement system based on a microwave wire mesh sensor, the electrolyte measurement system comprising:
a measurement channel loaded with a flowing electrolyte to be measured;
the wire mesh sensor is vertically arranged between two layers of metal wires to form a grid structure; one layer of metal wires is an emitter, the other layer of metal wires is a receiver, and the emitters and the receiver are mutually insulated;
a signal transmitting device for combining the emitter electrode and the receiver electrode by adjusting the electric signal;
the data acquisition equipment is a current detector and outputs a current signal of the combination of the emitter and the receiver to a computer processing system;
and the computer processing system is used for processing the acquired current signals to obtain a concentration value.
Preferably, the silk screen sensor adopts a grid cross structure, the interlayer spacing is 0.2-2 mm, and the distance between adjacent metal wires in the same layer is 0.5-4 mm.
Preferably, the metal wire is a hard metal wire with the thickness of 0.1-1 mm.
Preferably, the data acquisition equipment acquires a current signal generated by the receiving electrode, converts the current signal into a voltage signal through the transimpedance amplifier and the sample-and-hold circuit, converts the voltage signal into a digital signal through the analog-to-digital converter, and transmits the digital signal to the central control system, and the central control system stores the digital signal in a matrix form.
Preferably, the signal transmission device uses a rectangular pulse voltage as a driving voltage of the emitter, which is excited once in one cycle.
Preferably, the electrolyte solution measurement system is provided with impedances respectively at the output of the emitter and at the receiver adjacent to the emitter.
Preferably, the measuring channels are connected by flanges, and the wire mesh sensors are located on both sides of the pipe flange.
In a second aspect, the present invention provides a measurement method for measuring an electrolyte solution by using the electrolyte solution measurement system, the measurement method including the steps of:
step S1: calibrating and correcting the electrolyte solution with known concentration by an electrolyte solution measuring system to obtain a functional relation between the concentration of the electrolyte solution and the current of a silk screen receiving electrode;
step S2: measuring the measuring solution with unknown concentration by an electrolyte solution measuring system to obtain a receiver current value of the measuring solution;
step S3: and substituting the value of the receiver current of the measuring solution into the functional relation obtained in the step S1 to finally obtain the solution concentration of the measuring solution.
Preferably, the electrolyte solution is a solution having conductivity.
Preferably, in the step S1, the calibration process includes placing a static uniform solution in the measurement channel, obtaining a plurality of electrical signal values at different concentrations for each of the emitter and the receiver, and obtaining the functional relationship described in S1 according to the electrical signal values;
in the step S2, the measurement solution in the flow is collected by a signal collection device, and the concentration value is analyzed.
Compared with the prior art, the invention has the following advantages and beneficial effects:
the silk screen sensor is matched with the collected high-frequency electric signals, concentration information at a flow channel can be measured nearly in real time, the collection frequency can reach hundreds of hertz to thousands of hertz, and the data change condition in a short time can be captured. Due to the arrangement mode of the wire mesh, enough points can be measured, data of a plurality of points on one surface can be obtained, and then the data can be restored into two-dimensional data. Through a plurality of sensors, a plurality of different planes can be measured, and three-dimensional data can be obtained. The wires are thin enough to have little effect on the flow and can retain the original flow as true as possible.
Drawings
Other characteristic objects and advantages of the invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following figures.
FIG. 1 is a front and side view of the main body of a microwave wire mesh sensor-based electrolyte solution measurement system in one embodiment of the present invention;
FIG. 2 illustrates a circuit schematic of a wire mesh sensor;
FIG. 3 shows a control diagram of a signal;
FIG. 4 is a circular test section;
FIG. 5 is a measuring device;
FIG. 6 is a cloud of measured concentration results;
reference numerals:
a flow section 1; a bracket 2; and a screen sensor 3.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
Example 1
The embodiment relates to concentration measurement by adopting a wire mesh sensor, wherein the wire mesh sensor is made of double layers of parallel wire meshes, and the wires of the two layers of meshes are mutually vertical. One layer of metal wire is used as an emitter, the other layer of metal wire is used as a receiver, and the emitter and the receiver are mutually insulated. The wires are as thin as possible to reduce the effect on the flow field itself.
Fig. 1 is a front view and a side view of a main body of a screen sensor.
As shown in fig. 1, the spatial resolution of the screen sensor is closely related to the size of the spacing between the parallel electrodes, and the smaller the spacing, the higher the spatial resolution of the screen sensor; on the other hand, the smaller the spacing, the larger the number of wires required, the larger the voltage drop and the higher the disturbance, which affects the measurement accuracy, and the increased number of cross points of the measurement also puts higher requirements on the data acquisition frequency.
Taking a 4 × 4 silk screen sensor as an example, fig. 2 shows a schematic circuit diagram of the silk screen sensor. The basic principle is as follows: successive pulses sequentially excite the emitters through switches S1-S4 (the number of switches is the same as the number of wires per layer, in this example, a 16x16 wire mesh sensor, and the emitters are sequentially excited through 16 switches), and corresponding current signals are generated by the corresponding receivers, which reflect the conductivity of the local fluid (current is proportional to conductivity). All the emitting electrodes are excited once in one period, the corresponding receiving electrodes convert the generated current signals into voltage signals through the trans-impedance amplifier and the sampling and holding circuit, the voltage signals are converted into digital signals through the analog-to-digital converter, and the digital signals are transmitted to a computer and stored in a matrix form. The matrix reflects the two-dimensional distribution of the conductivity at the measurement cross-section.
Since the electrolytic effect of the metal conductor can occur when the direct current is continuously introduced into the water and the measurement result is subject to error, the rectangular pulse voltage is supposed to be used as the driving voltage of the emitter in the embodiment. The rectangular pulse voltage is generated by switching of the changeover switch SP, and a jump occurs at the midpoint instant of the active period of the emitter (an active period refers to the time during which one switch lasts from being closed to being opened).
Fig. 3 shows a control diagram of signals, when the switch S2 is closed, the second electrode is excited, and four receiving electrodes generate four transient currents IR1, IR2, IR3 and IR4, and fig. 6 shows changes of the emitter voltage and the second receiving electrode current (where (a) to (d) respectively represent transient currents IR1 to IR4), i.e., the emitter and the receiving electrode corresponding to the intersection (2, 2) in fig. 3. At the instant the emitter is excited, a capacitor is formed by the instant the emitter and the receiver are charged. The current in the circuit will decrease and stabilize over time, depending on the discharge characteristics of the capacitor. The current signal is converted into a voltage signal by a transimpedance amplifier. When the current is in a stable level, a subsequent sampling/holding circuit is triggered to temporarily store the voltage signal, and finally, the analog signal is converted into a digital signal through an analog-to-digital converter and the result is transmitted to a computer for storage.
In order to avoid the influence of parasitic current caused by triggering of parallel emitters on the adjacent side when the emitter is triggered on a measurement result, the output end and the receiving end of the emitter drive are provided with impedances which are far lower than the impedance of the conductive fluid, and the potentials of other emitters and receiving electrodes except the excited emitter are ensured to be zero, so that the influence of the parasitic current is eliminated.
The concentration distribution of boric acid in the T-tube was measured. Therefore, the pipeline is made of organic glass material, and the specific structure of the pipeline is shown in figure 4. It should be noted that flanges are used for connecting the pipelines in fig. 4, so that a silk screen sensor body can be added between the two flanges, and the inner diameter of the single-tube axial test body is 70mm, and the length is 1000 mm. The concentration range of the studied boric acid is 0-2000 ppm.
In order to avoid affecting the flow field as much as possible and ensure the mechanical strength of the silk screen sensor, the silk screen sensor is designed by adopting stainless steel wires with the diameter of 0.1 mm.
In summary, a wire mesh structure of 16 × 16 is adopted, and the structure of the wire mesh sensor is shown in fig. 1, that is, the emitter and the receiver are 16 stainless steel wires each with 0.1mm, the parallel distance is 4mm, the axial distance between two planes is 2mm, and the stainless steel wires are welded on the integrated board after being tensioned by adopting a welding technology, and the inner diameter dimension is 60mmx60 mm. According to the experimental working condition and requirement to be measured, the designed acquisition frequency is 200Hz, namely, each intersection point generates 200 data per second.
This example requires measurement of the concentration of boric acid, and the measurement structure can be referred to fig. 5. As shown in fig. 5, the support 2 is used for fixing the flow section 1, and calibration are performed when the flow section 1 flows through the wire mesh sensor 3.
During measurement, the concentration of the boric acid solution is adopted for calibration and calibration. Boric acid solutions (from 0ppm to 2000ppm) were prepared at different concentrations, respectively.
The following steps are adopted during measurement:
step S1: calibrating and correcting the electrolyte solution with known concentration by an electrolyte solution measuring system to obtain a functional relation between the concentration of the electrolyte solution and the current of a silk screen receiving electrode;
step S2: measuring the measuring solution with unknown concentration by an electrolyte solution measuring system to obtain a receiver current value of the measuring solution;
step S3: and substituting the value of the receiver current of the measuring solution into the functional relation obtained in the step S1 to finally obtain the solution concentration of the measuring solution.
In step S1, the calibration process includes placing a static uniform solution in the measuring device, obtaining a plurality of electrical signal values at different concentrations for each of the emitter and the receiver, and obtaining the functional relationship described in S1 according to the electrical signal values;
in the step S2, the measurement solution (i.e., the flow segment 1) in the flow is collected by a signal collection device, and the concentration value is analyzed.
In the calibration experiment, the functional relationship between the boron concentration and the screen receiver current is obtained, so that the calibrated screen sensor 3 can be directly used for measuring the boron concentration distribution in the experimental section in real time, and fig. 6 is a cloud chart of the measured concentration result.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.
Claims (10)
1. Electrolyte solution measurement system based on microwave silk screen sensor, characterized in that, electrolyte measurement system includes:
a measurement channel loaded with a flowing electrolyte to be measured;
the wire mesh sensor is vertically arranged between two layers of metal wires to form a grid structure; one layer of metal wires is an emitter, the other layer of metal wires is a receiver, and the emitters and the receiver are mutually insulated;
a signal transmitting device for combining the emitter electrode and the receiver electrode by adjusting the electric signal;
the data acquisition equipment is a current detector and outputs a current signal of the combination of the emitter and the receiver to a computer processing system;
and the computer processing system is used for processing the acquired current signals to obtain a concentration value.
2. The electrolyte solution measuring system of claim 1, wherein the wire mesh sensor has a grid cross structure, the distance between layers is 0.2-2 mm, and the distance between adjacent wires in the same layer is 0.5-4 mm.
3. The electrolyte solution measuring system according to claim 1, wherein the wire is a hard wire of 0.1 to 1 mm.
4. The electrolyte solution measuring system according to claim 1, wherein the data acquisition device acquires a current signal generated from the receiver electrode, converts the current signal into a voltage signal through the transimpedance amplifier and the sample-and-hold circuit, converts the voltage signal into a digital signal through the analog-to-digital converter, and transmits the digital signal to the central control system, and the central control system stores the digital signal in a matrix form.
5. The electrolyte solution measuring system according to claim 1, wherein the signal transmission device employs a rectangular pulse voltage as a driving voltage of the emitter, which is excited once in one cycle.
6. The electrolyte solution measurement system of claim 1, wherein the electrolyte solution measurement system is provided with impedances at the output of the emitter and at the receiver adjacent to the emitter, respectively.
7. The electrolyte solution measurement system of claim 1, wherein the measurement channel is flanged, and the wire mesh sensors are located on both sides of a pipe flange.
8. A measuring method for electrolyte solution measurement using the electrolyte solution measuring system according to any one of claims 1 to 7, characterized by comprising the steps of:
step S1: calibrating and correcting the electrolyte solution with known concentration by an electrolyte solution measuring system to obtain a functional relation between the concentration of the electrolyte solution and the current of a silk screen receiving electrode;
step S2: measuring the measuring solution with unknown concentration by an electrolyte solution measuring system to obtain a receiver current value of the measuring solution;
step S3: and substituting the value of the receiver current of the measuring solution into the functional relation obtained in the step S1 to finally obtain the solution concentration of the measuring solution.
9. The measurement method according to claim 8, wherein the electrolyte solution is a solution having conductivity.
10. The method of claim 8, wherein in step S1, the calibration procedure is to place a static homogeneous solution in the measurement channel, obtain a plurality of electrical signal values at different concentrations for each emitter and receiver, and obtain the functional relationship of S1 according to the electrical signal values;
in the step S2, the measurement solution in the flow is collected by a signal collection device, and the concentration value is analyzed.
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US4644263A (en) * | 1984-12-13 | 1987-02-17 | Marathon Oil Company | Method and apparatus for measuring water in crude oil |
CN101650328A (en) * | 2009-09-14 | 2010-02-17 | 天津大学 | Measuring apparatus for multiphase fluid imaging based on bimodal silk screen and measuring method thereof |
CN110763704A (en) * | 2019-11-20 | 2020-02-07 | 天津工业大学 | Microwave Wire mesh-based oil-water two-phase flow water content measuring system |
CN211577013U (en) * | 2019-11-20 | 2020-09-25 | 天津工业大学 | Oil-water two-phase flow water content measuring system based on microwave silk screen sensor |
CN112378980A (en) * | 2020-11-12 | 2021-02-19 | 上海交通大学 | Correction system and method for silk screen probe concentration detection device |
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- 2021-06-16 CN CN202110668398.6A patent/CN113466312A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4644263A (en) * | 1984-12-13 | 1987-02-17 | Marathon Oil Company | Method and apparatus for measuring water in crude oil |
CN101650328A (en) * | 2009-09-14 | 2010-02-17 | 天津大学 | Measuring apparatus for multiphase fluid imaging based on bimodal silk screen and measuring method thereof |
CN110763704A (en) * | 2019-11-20 | 2020-02-07 | 天津工业大学 | Microwave Wire mesh-based oil-water two-phase flow water content measuring system |
CN211577013U (en) * | 2019-11-20 | 2020-09-25 | 天津工业大学 | Oil-water two-phase flow water content measuring system based on microwave silk screen sensor |
CN112378980A (en) * | 2020-11-12 | 2021-02-19 | 上海交通大学 | Correction system and method for silk screen probe concentration detection device |
Non-Patent Citations (7)
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Application publication date: 20211001 |