CN115452237B - Novel pipeline liquid pressure testing method and device - Google Patents
Novel pipeline liquid pressure testing method and device Download PDFInfo
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- CN115452237B CN115452237B CN202211128396.9A CN202211128396A CN115452237B CN 115452237 B CN115452237 B CN 115452237B CN 202211128396 A CN202211128396 A CN 202211128396A CN 115452237 B CN115452237 B CN 115452237B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/02—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Abstract
The invention belongs to the technical field of pipeline transportation, and particularly relates to a novel pipeline liquid pressure testing method and device. The testing device comprises a liquid pressure sensor, a microprocessor and a display module; the liquid pressure sensor includes: a sensing electrode, a reference electrode and a signal processing module which are formed by metal and oxide thereof; the signal processing module filters and amplifies the obtained voltage signal and converts the voltage value through the A/D acquisition module; the microprocessor is a microprocessor integrated with a pressure prediction model and is used for converting the voltage value into a liquid pressure value; and the display module acquires and displays the liquid pressure value or/and the voltage value. The device has the characteristics of high sensitivity, simple structure, low cost and energy conservation; the method is suitable for continuous liquid pressure monitoring under static and dynamic conditions.
Description
Technical Field
The invention belongs to the technical field of pipeline transportation, and particularly relates to a novel pipeline liquid pressure testing method and device; the method is applied to the fields of medical diagnosis, chemical production, deep sea pipeline transportation, petroleum transportation and the like.
Background
The measurement of the liquid pressure of the pipeline is important in the fields of medical diagnosis, chemical production, deep sea pipeline transportation, petroleum transportation and the like; moreover, the density, viscosity, level, etc. parameters of the liquid in the container are often also required to be measured based on the liquid pressure sensor.
Traditional hydrostatic-based liquid column pressure gauges, which are usually composed of graduated glass tubes, require manual on-site data reading and are only suitable for low liquid pressure measurements in conventional environments. With the progress of technology, liquid pressure measurement methods based on various piezoelectric, piezoresistive and capacitive sensors are gradually developed. They are usually composed of sensitive elements, connection circuits and protective shells, and the method is used for measuring the pressure of the liquid in various closed pipelines and containers at present. However, long-term monitoring in some high-temperature, high-pressure, high-corrosion extreme liquid environments requires a tightly designed protective enclosure, which can greatly affect the sensitivity and response time of the sensor, etc. Meanwhile, the piezoelectric pressure sensor cannot measure static pressure; capacitive pressure sensors are difficult to miniaturize because of their large structural volume. In addition to the above methods, some new liquid pressure measurement methods based on optical fibers, ultrasonic and visual sensors have also evolved dramatically, but these methods have not been well applied due to the requirements of measurement accuracy, service life, pipe installation requirements, and equipment complexity.
Disclosure of Invention
In order to solve the technical problems, the invention provides a sensing electrode based on the solid-liquid junction double electric layer principle, wherein the thickness of the formed double electric layer is different under the condition of different pressures, the electric potentials of the surfaces of the electrodes are different, and the pressure measurement of liquid in a pipeline under different states is realized.
In order to achieve the above purpose, the embodiment of the invention provides a novel pipeline liquid pressure testing device, which comprises a liquid pressure sensor, a microprocessor and a display module;
the liquid pressure sensor includes: a sensing electrode, a reference electrode and a signal processing module which are formed by metal and oxide thereof; one end of the sensing electrode is in contact with the liquid, and the other end of the sensing electrode is connected with a lead to lead out a voltage signal and is fixed on a pipeline; the signal processing module filters and amplifies the obtained voltage signal and converts the voltage value through the A/D acquisition module;
the microprocessor is a microprocessor integrated with a pressure prediction model and is used for converting the voltage value into a liquid pressure value;
and the display module acquires and displays the liquid pressure value or/and the voltage value.
Further, the metal in the sensing electrode formed by the metal and the oxide thereof is any one of tungsten, tantalum, molybdenum, titanium, niobium or platinum. Further, the reference electrode is an electrode capable of providing stable potential in liquid, and comprises a saturated Ag/AgCl electrode, a calomel electrode, a SiC electrode or the like.
Further, the signal processing circuit includes a voltage following, filtering and amplifying circuit.
Based on the same inventive concept, the embodiment of the invention also provides a novel pipeline liquid pressure testing method, which specifically comprises the following steps:
s1, installing a liquid pressure sensor on the inner surface of a simulation pipeline, and measuring voltage values under different states by adjusting the states of liquid in the simulation pipeline;
s2, measuring the liquid pressure values in different states in the step S1 by adopting a high-precision resistance type pressure sensor;
s3, performing linear fitting according to the liquid pressure values and the corresponding voltage values in different states to obtain corresponding pressure prediction models;
and S4, integrating the pressure prediction model into a microprocessor, installing a liquid pressure sensor on the inner surface of the pipeline to be measured during measurement, accessing the microprocessor and a display module, measuring a voltage value, and reading the liquid pressure of the pipeline to be measured.
Further, the different states in step S2 specifically include: different liquid media, liquid static, liquid dynamic at different flow rates.
Further, the step of installing the liquid pressure sensor on the inner surface of the pipe specifically includes:
one end of a sensing electrode of the hydraulic sensor is directly contacted with liquid, the other end of the sensing electrode is connected with a lead to lead out an electric signal, an insulating sealing waterproof interface is arranged at the middle joint, the sensing electrode passes through a pressure pipeline and is fixed on the pipeline when being installed, and a sealing interface is arranged at the middle joint, specifically through a waterproof threaded interface and a glue sealing mode.
The beneficial effects are that:
the pipeline liquid pressure measuring method and device based on the solid-liquid junction double electric layer principle have the characteristics of high sensitivity, simple structure, low cost and energy conservation; the method is suitable for continuous liquid pressure monitoring under static and dynamic conditions; meanwhile, the sensing electrode directly contacts the liquid to sense the pressure, the response time is short, the linearity is good, the property is stable, the sensing electrode is not easy to damage in an all-solid state, and the sensing electrode can be placed in the liquid for a long time to measure; the signal output by the liquid pressure sensor is an open-circuit voltage value, the open-circuit voltage value acquisition technology is mature, the transmission distance is not limited, and the measuring device is convenient to design and develop towards the intelligent direction.
Drawings
Fig. 1 is a schematic diagram of a pipeline liquid pressure measurement device based on a solid-liquid double layer hydraulic sensor according to an embodiment of the present invention;
fig. 2 is a schematic diagram illustrating a structure of a solid-liquid double electric layer sensing electrode according to an embodiment of the present invention;
FIG. 3 is a graph showing the static pressure response of tap water based on tungsten/tungsten oxide liquid pressure sensor according to example 1 of the present invention;
FIG. 4 is a graph showing the dynamic pressure response of tap water based on tungsten/tungsten oxide liquid pressure sensor according to example 2 of the present invention;
FIG. 5 is a graph showing the dynamic pressure response of a 0.1mol/L KCL solution based on a tungsten/tungsten oxide liquid pressure sensor according to example 3 of the present invention;
fig. 6 is a graph of glycerin and purified water 1 based on a tungsten/tungsten oxide liquid pressure sensor according to example 4 of the present invention: 2, a hybrid dynamic pressure response characteristic;
the specific identification in the drawings is as follows:
1-1, a sensing electrode; 1-2, a reference electrode; 1-3, a signal processing module; 1-4, a microprocessor; 1-5, a liquid storage tank; 1-6, peristaltic pump; 1-8, a display module.
Detailed Description
For a clearer explanation of the technical content of the present invention, reference is made to the detailed description herein with reference to specific examples and drawings, it being evident that the examples cited are only preferred embodiments of the present technical solution, and that other technical solutions obvious to those skilled in the art from the disclosed technical content still fall within the scope of the present invention.
In the embodiment of the invention, as shown in fig. 1, a set of pipeline liquid pressure measuring device based on an MSP430F5438 microprocessor is provided, a sensing electrode 1-1 is in direct contact with liquid, an electric double layer with the thickness of tens to hundreds of nanometers is formed on the surface, the liquid pressure is different, the thickness of the formed electric double layer is different, and therefore, the electric potential of the electrode surface is also different; the reference electrode 1-2 provides a reference potential, the potential of which does not change with the pressure of the liquid; the voltage signal processing module 1-3 filters and amplifies an open-circuit voltage value between the sensing electrode 1-1 and the reference electrode 1-2, and converts the digital voltage value through the A/D acquisition module, wherein the microprocessor 1-4 is a microprocessor integrated with a pressure prediction model and is used for converting the digital voltage value into a liquid pressure value; display is performed on the display modules 1-8. In order to carry out experimental verification on the pipeline liquid pressure measuring device, a hose is laid on a horizontal tabletop, two ends of the hose are respectively connected with a liquid storage tank 1-5, and a liquid static-dynamic pressure testing environment is created by continuously extruding the hose through a peristaltic pump 1-6.
The sensing electrode is prepared by chemical oxidation and electrochemical oxidation, and in the embodiment of the invention, the preparation method of the sensing electrode is as follows: metal tungsten/tantalum/molybdenum electrode with purity more than 99.99% is added with H of 0.1mol/L 2 SO 4 In the solution, electrochemical oxidation is carried out for 15-30 times by using a cyclic voltammetry, the scanning voltage is 1-2-1V, and the scanning speed is 0.02-0.1V/s. The prepared metal oxide electrode is led out through a wire and connected to a back-end circuit, and the joint of the electrode and the wire needs sealing treatment to prevent the contact with water. The prepared sensing electrode is contacted with liquid, an electric double layer is formed on the surface, the liquid pressure is different, and the thickness of the formed electric double layer is different, so that the electric potential of the electrode surface is different; the greater the liquid pressure, the thinner the electric double layer thickness and the smaller the sensing electrode potential. The reference electrode comprises a saturated Ag/AgCl electrode, a calomel electrode, a SiC electrode and the like, and the potential in the liquid is unchanged, so that the reference potential is provided.
The following describes specific test methods in specific examples
Example 1
The structure of the sensing electrode and the installation schematic diagram in a pipeline are shown in figure 2, one end of the sensing material tungsten/tungsten oxide 2-1 is in direct contact with liquid, the other end of the sensing material tungsten/tungsten oxide 2-1 is connected with a wire to lead out an electric signal, and the sensing material tungsten/tungsten oxide 2-1 and the wire are subjected to insulation-waterproof encapsulation through a heat-shrinking polytetrafluoroethylene sleeve 2-2. Meanwhile, the sensing electrode needs to penetrate through a pressure pipeline and be fixed on the surface of the pipeline during installation, and the middle connection interface 2-3 is sealed and fixed in a glue sealing mode. If the liquid pressure is too high, a waterproof screwed joint with a fastened structure is needed. A saturated Ag/AgCl electrode was chosen as reference electrode in this example.
As shown in the integral device in figure 1, tap water at 25 ℃ is filled in a pipeline, the pressure force of a peristaltic pump is kept unchanged, liquid in the pipeline does not flow, different static pressures are provided by changing the arrangement positions 1-7 of tungsten/tungsten oxide sensing electrodes, and the output voltage of a liquid pressure sensor under the different static pressures is recorded and stored; the output voltages of the liquid pressure sensors at the five distribution positions shown in 1-7 are respectively-0.3186, -0.3099, -0.2999, -0.2916 and-0.2838 (V).
The device was calibrated using a high precision resistive pressure sensor to determine pressure data at different static pressures. The static pressure (gauge pressure = absolute pressure-atmospheric pressure) for each location point was-3.10162, -3.02793, -2.97453, -2.9407, -2.90048 (kpa), respectively. The adopted high-precision resistance type pressure sensor is an AE-S micro pressure sensor of Nanjing Air sensing, the measuring range is-30 kpa to 30kpa (gauge pressure), the measuring precision is 0.5%, and the measuring requirement is met.
And carrying out linear fitting on the obtained pressure data and voltage data to obtain a static pressure prediction model, wherein a characteristic curve is shown in fig. 3, and an equation is specifically as follows:
y＝--1.42374+5.20823*x (1)
x is the output voltage (unit is V) of the tungsten/tungsten oxide-based liquid pressure sensor, and y is the liquid pressure value (unit is kpa) to be measured.
The prediction model is integrated into a microprocessor, a liquid pressure sensor is arranged on the inner surface of a static water pipeline to be detected, the microprocessor and a display module are connected, and the pressure value is directly read.
Example 2
The structure of the sensing electrode and the installation schematic diagram in a pipeline are shown in figure 2, one end of the sensing material tungsten/tungsten oxide 2-1 is in direct contact with liquid, the other end of the sensing material tungsten/tungsten oxide 2-1 is connected with a wire to lead out an electric signal, and the sensing material tungsten/tungsten oxide 2-1 and the wire are subjected to insulation-waterproof encapsulation through a heat-shrinking polytetrafluoroethylene sleeve 2-2. Meanwhile, the sensing electrode needs to penetrate through a pressure pipeline and be fixed on the surface of the pipeline during installation, and the middle connection interface 2-3 is sealed and fixed in a glue sealing mode. If the liquid pressure is too high, a waterproof screwed joint with a fastened structure is needed. A saturated Ag/AgCl electrode was chosen as reference electrode in this example.
As shown in the whole device in FIG. 1, the pipeline is filled with tap water at 25 ℃, the flow rates of peristaltic pumps are changed to be 500, 400, 300, 200, 100, 0, -100, -200, -300, -400 and 500 (mL/min) respectively so as to provide different dynamic pressures, the output voltages of the liquid pressure sensors under the different dynamic pressures are recorded and stored, and the output voltages of the liquid pressure sensors are respectively-0.3029, -0.29313, -0.28286, -0.27462, -0.26506, -0.254, -0.2419, -0.23121, -0.22127, -0.2101 and-0.202 (V).
The device was calibrated using high precision resistive pressure sensors and the corresponding dynamic pressures (gauge pressure = absolute pressure-atmospheric pressure) were measured to be-3.00204, -2.9514, -2.90876, -2.84132, -2.77532, -2.72464, -2.65104, -2.6088, -2.56868, -2.52108, -2.48784 (kpa), respectively.
And performing linear fitting on the obtained pressure data and voltage data to obtain a dynamic pressure prediction model, wherein a characteristic curve is shown in fig. 4, and an equation is specifically as follows:
y＝-1.40176+5.21187*x (2)
x is the output voltage (unit is V) of the tungsten/tungsten oxide-based liquid pressure sensor, and y is the liquid pressure value (unit is kpa) to be measured.
Example 3
The structure of the sensing electrode and the installation schematic in the pipe were the same as those of examples 1 and 2 using the tungsten/tungsten oxide electrode as the sensing electrode. As shown in the experimental device in FIG. 1, the pipeline is filled with 0.1mol/L KCL solution, the flow rates of peristaltic pumps are changed to be 0, 100, 200, 300, 400 and 500 (mL/min) respectively, so as to provide different dynamic pressures, the output voltages of the liquid pressure sensors under different dynamic pressures are recorded and stored, and the output voltages of the liquid pressure sensors are-0.25569, -0.25295, -0.25033, -0.24757, -0.24529, -0.24189 (V) respectively.
The device was calibrated using a high-precision resistive pressure sensor, measuring the corresponding pressures (gauge pressure = absolute pressure-atmospheric pressure) of-2.77813, -2.70306, -2.65934, -2.61987, -2.57054 (kpa), respectively, in 0.1mol/L KCL solution.
Performing linear fitting on the obtained pressure data and voltage data to obtain a liquid pressure prediction model in 0.1mol/L KCL solution, wherein a characteristic curve is shown in FIG. 5, and an equation is specifically as follows:
y＝1.90139+18.26337*x (3)
x is the output voltage (unit is V) of the tungsten/tungsten oxide-based liquid pressure sensor, and y is the liquid pressure value (unit is kpa) to be measured.
Example 4
The structure of the sensing electrode and the installation schematic in the pipe are the same as those of examples 1, 2 and 3 with tungsten/tungsten oxide electrode as the sensing electrode. As in the experimental set-up shown in fig. 1, the tubing is filled with glycerol and purified water 1:2, changing the flow rates of peristaltic pumps to be 0, 100, 200, 300, 400 and 500 (mL/min) respectively so as to provide different dynamic pressures, recording and storing the output voltages of the liquid pressure sensors under different dynamic pressures, wherein the output voltages of the liquid pressure sensors are-0.19452, 0.06512, 0.32367, 0.55784, 0.78594 and 0.95015 (V) respectively.
The device was calibrated using a high precision resistive pressure sensor, in glycerol with purified water 1:2, and the corresponding pressures are respectively-2.86187, -2.7837, -2.73995, -2.69791, -2.64803, -2.61302 (kpa).
And (3) performing linear fitting on the obtained pressure data and voltage data to obtain a liquid pressure prediction model in a mixed solution of glycerin and purified water in a ratio of 1:2, wherein a characteristic curve is shown in fig. 6, and an equation is specifically as follows:
y＝-2.8150+0.2143*x (4)
x is the output voltage (unit is V) of the tungsten/tungsten oxide-based liquid pressure sensor, and y is the liquid pressure value (unit is kpa) to be measured. As can be seen from the above embodiments, the tungsten/tungsten oxide liquid pressure sensor is in the same liquid, and its static and dynamic pressure prediction models show consistency; in different liquids, the pressure prediction models are different and all linear. The different prediction models are integrated into the microprocessor, the liquid pressure sensor is arranged on the inner surface of the dynamic water pipeline to be measured, the microprocessor and the display module are connected, the pressure value is directly read, and the measuring method and the measuring device are feasible and high in reliability.
The above embodiments are only preferred embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to apply equivalents and modifications according to the technical solution and the concept of the present invention within the scope of the present invention.
Claims (4)
1. The pipeline liquid pressure testing device is characterized by comprising a liquid pressure sensor, a microprocessor and a display module;
the liquid pressure sensor includes: a sensing electrode, a reference electrode and a signal processing module which are formed by metal and oxide thereof; one end of the sensing electrode is in contact with the liquid, and the other end of the sensing electrode is connected with a lead to lead out a voltage signal and is fixed on a pipeline; the signal processing module filters and amplifies the obtained electric signal and converts the voltage value through the A/D acquisition module;
the microprocessor is a microprocessor integrated with a pressure prediction model and is used for converting the voltage value into a liquid pressure value;
the display module acquires and displays the liquid pressure value or/and the voltage value;
the testing method of the pipeline liquid pressure testing device specifically comprises the following steps:
s1, installing a liquid pressure sensor on the inner surface of a simulation pipeline, and measuring voltage values under different states by adjusting the states of liquid in the simulation pipeline; the different states specifically include: different liquid media, liquid static state and dynamic state under different flow rates of liquid;
s2, measuring the liquid pressure values in different states in the step S1 by adopting a high-precision resistance type pressure sensor;
s3, performing linear fitting according to the liquid pressure values and the corresponding voltage values in different states to obtain corresponding pressure prediction models;
and S4, integrating the pressure prediction model into a microprocessor, installing a liquid pressure sensor on the inner surface of the pipeline to be measured during measurement, accessing the microprocessor and a display module, measuring a voltage value, and reading the liquid pressure of the pipeline to be measured.
2. The device according to claim 1, wherein the metal in the sensing electrode made of the metal and the oxide thereof is any one of tungsten, tantalum, molybdenum, titanium, niobium, or platinum.
3. The device according to claim 1, wherein the reference electrode is an electrode capable of providing a stable potential in a liquid, comprising a saturated Ag/AgCl electrode, a calomel electrode, or a SiC electrode.
4. The apparatus of claim 1, wherein the means for mounting the fluid pressure sensor on the inner surface of the conduit comprises:
one end of a sensing electrode of the liquid pressure sensor is directly contacted with liquid, the other end of the sensing electrode is connected with a lead to lead out an electric signal, an insulating sealing waterproof interface is arranged at the middle joint, the sensing electrode passes through a pressure pipeline and is fixed on the pipeline when being installed, a sealing interface is arranged at the middle joint, and the sealing interface is a waterproof threaded interface or an interface manufactured in a glue sealing mode.
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Citations (4)
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|---|---|---|---|---|
| US4821564A (en) * | 1986-02-13 | 1989-04-18 | Atlantic Richfield Company | Method and system for determining fluid pressures in wellbores and tubular conduits |
| CN104459195A (en) * | 2014-12-02 | 2015-03-25 | 浙江大学 | Device and method for measuring ultralow liquid flow rate |
| CN110763866A (en) * | 2019-11-11 | 2020-02-07 | 湖南大学 | Liquid phase flow velocity measuring device and method |
| CN113049848A (en) * | 2021-03-31 | 2021-06-29 | 隋卓君 | Portable current meter based on numerical simulation and pressure sensor |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2726827B1 (en) * | 2011-06-30 | 2019-12-11 | University of Canterbury | Flow rate determination method and apparatus |
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4821564A (en) * | 1986-02-13 | 1989-04-18 | Atlantic Richfield Company | Method and system for determining fluid pressures in wellbores and tubular conduits |
| CN104459195A (en) * | 2014-12-02 | 2015-03-25 | 浙江大学 | Device and method for measuring ultralow liquid flow rate |
| CN110763866A (en) * | 2019-11-11 | 2020-02-07 | 湖南大学 | Liquid phase flow velocity measuring device and method |
| CN113049848A (en) * | 2021-03-31 | 2021-06-29 | 隋卓君 | Portable current meter based on numerical simulation and pressure sensor |
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