Calibration device and method for liquid film thickness measuring instrument under high-temperature and high-pressure conditions

Abstract

The invention discloses a liquid film thickness measuring instrument calibration device and method under high-temperature and high-pressure conditions, and belongs to the technical field of measurement. The liquid film thickness measuring instrument calibration device under the high-temperature and high-pressure conditions comprises a pressure container, a calibration platform and a heating module, the calibration platform and the heating module are arranged in the pressure container, a pressurizing device provides a pressure environment in the pressure container, and the heating module heats a standard solution in the pressure container; the calibration platform is immersed in a standard solution and comprises an alumina ceramic first clamping plate and an alumina ceramic second clamping plate which are at least partially overlapped, and a standard solution film is formed between the first clamping plate and the second clamping plate. The device can provide a stable high-temperature and high-pressure environment and a standard solution liquid film with accurate thickness for the to-be-calibrated liquid film thickness measuring instrument, and the calibration precision of the liquid film thickness measuring instrument under the high-temperature and high-pressure working condition is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of measurement, and particularly relates to a calibration device and method for a liquid film thickness measuring instrument under high temperature and high pressure conditions. Background Art

[0002] In fields such as chemical engineering, the liquid film thickness is an important parameter affecting physical and chemical processes. Therefore, it is necessary to accurately measure the thickness of the liquid film using a liquid film thickness measuring instrument. Usually, the liquid film thickness can be measured by the electrical method, and based on physical parameters such as conductivity, resistivity, or capacitance, the thickness of the liquid film is deduced. The accuracy of measuring the liquid film thickness by the electrical method depends on the calibration accuracy of the measuring instrument. It is necessary to measure the standard liquid multiple times under different parameters to establish a calibration data set before the measuring instrument can be used for the actual measurement of the liquid film thickness. However, existing calibration devices can usually only be calibrated at normal temperature and pressure, and cannot carry out calibration work for high temperature and high pressure environments, which affects the accuracy of measuring the liquid film thickness under high temperature and high pressure conditions. Therefore, providing a device capable of calibrating a liquid film thickness measuring instrument under high temperature and high pressure conditions is of positive significance for improving the accuracy of measuring the liquid film thickness under high temperature and high pressure conditions. Summary of the Invention

[0003] The purpose of the present invention is to provide a calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions to improve the measurement accuracy of the liquid film thickness under high temperature and high pressure conditions. The present invention also provides a calibration method for a liquid film thickness measuring instrument under high temperature and high pressure conditions.

[0004] According to an embodiment of one aspect of the present invention, there is provided a calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions. The device includes a pressure vessel, a calibration platform, a pressurizing device, and a heating module;

[0005] Wherein, the calibration platform and the heating module are arranged inside the pressure vessel. The pressurizing device is connected to the pressure vessel and forms a pressure environment inside the pressure vessel. A standard solution is contained inside the pressure vessel, and the standard solution submerges the calibration platform;

[0006] The calibration platform includes a first clamping plate and a second clamping plate made of alumina ceramics. The first clamping plate and the second clamping plate at least partially overlap in the vertical direction. A clamping plate gap is formed in the overlapping area of the first clamping plate and the second clamping plate, and a standard solution liquid film is formed inside the clamping plate gap;

[0007] The heating module is used to heat the standard solution.

[0008] This device can accurately control the temperature and pressure inside the pressure vessel, thereby providing a stable high-temperature and high-pressure calibration environment; a standard solution liquid film is provided through the gap between the first clamping plate and the second clamping plate, eliminating the need for a large-volume micrometer and effectively reducing the space requirements of the pressure vessel; the first clamping plate and the second clamping plate are made of alumina ceramics, with a thermal expansion coefficient of only 5×10 -6 -8×10 -6 / ℃, effectively avoiding the influence of thermal expansion on the test accuracy.

[0009] Further, in some embodiments, the width of the clamping plate gap is set to be adjustable.

[0010] Further, in some embodiments, an adjustment bolt is provided between the first clamping plate and the second clamping plate, and the clamping plate gap is adjusted by rotating the adjustment bolt.

[0011] Further, in some embodiments, the first clamping plate and the second clamping plate are provided as independent parts.

[0012] Further, in some embodiments, the pressurizing device is configured as a high-pressure gas cylinder.

[0013] Further, in some embodiments, the heating module is configured as an electric heating device, and the heating module is provided below the calibration platform.

[0014] Further, in some embodiments, a through data line channel is provided on the pressure vessel to allow the data line to extend from inside the pressure vessel to outside the pressure vessel.

[0015] Further, in some embodiments, the first clamping plate is provided below the second clamping plate, and a through mounting hole is provided on the first clamping plate for mounting the liquid film thickness measuring instrument to be calibrated.

[0016] According to an embodiment of another aspect of the present invention, a method for calibrating a liquid film thickness measuring instrument under high-temperature and high-pressure conditions is provided. This method uses the liquid film thickness measuring instrument calibration device under high-temperature and high-pressure conditions provided in any of the foregoing embodiments to calibrate the liquid film thickness measuring instrument to be calibrated.

[0017] Further, the liquid film thickness measuring instrument to be calibrated is configured as an electrical liquid film thickness measuring instrument. Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of a liquid film thickness measuring instrument calibration device under high-temperature and high-pressure conditions in an embodiment.

[0019] Meanings of the reference numerals: 1 - pressure vessel; 2 - heating module; 3 - calibration platform; 4 - adjusting bolt; 5 - liquid film thickness measuring instrument; 6 - signal acquisition data line; 7 - measuring instrument replacement duct; 8 - pressure regulating pipeline; 9 - pressure regulating valve; 10 - nitrogen cylinder; 11 - flange; 12 - water inlet; 13 - water outlet; 14 - bracket; 15 - upper computer; 16 - first clamping plate; 17 - second clamping plate; 18 - top cover.

[0020] The purpose of the above-mentioned drawings is to illustrate the present invention in detail so that those skilled in the art can understand the technical concept of the present invention, rather than to limit the present invention. For the sake of brevity of expression, the above-mentioned drawings only schematically show the structures related to the technical features of the present invention, and do not strictly draw the complete structure and all details in actual proportion. Specific embodiments

[0021] The present invention will be further described in detail below through specific embodiments in conjunction with the drawings.

[0022] The mention of "embodiment" in this article means that the specific features, structures or characteristics described in connection with the embodiment may be included in at least one embodiment of this article. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments in this article can be combined with other embodiments without structural conflict.

[0023] In the description of this article, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a movable connection, a fixed connection or an integral body. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific situations.

[0024] In the description of this article, terms indicating orientation or position relationship such as "upper", "lower", "left", "right", "horizontal", "longitudinal", "height", "length", "width", etc. are intended to accurately describe the embodiment and simplify the description, rather than to limit that the parts or structures involved must have a specific orientation, be installed or operated in a specific orientation, and cannot be understood as a limitation to the embodiments in this article.

[0025] In the description of this article, terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "a plurality" is at least two.

[0026] In the fields of chemical industry, nuclear power, biomedicine, wastewater treatment, etc., there are a large number of reaction processes carried out in liquid films in devices such as evaporators and condensers. The thickness of the liquid film affects the mass transfer rate and reaction rate of the reactants, and the thickness of the liquid film determines the transmission rate of the substance between the phase interfaces; in catalytic reactions, the thickness of the liquid film affects the contact area and reaction rate of the reactants. The appropriate thickness of the liquid film can promote the reaction and improve production efficiency; at the same time, the thickness of the liquid film has an important influence on the design and operating conditions of the equipment. In liquid-liquid reactions and gas-liquid reactions, the thickness of the liquid film directly affects the effectiveness of the reaction; in the wastewater treatment process, the thickness of the liquid film is closely related to the removal efficiency of pollutants; in evaporators and condensers, the thickness of the liquid film affects the transfer rate of heat and substances, and thus affects the energy consumption of the device. In addition, the thickness of the liquid film has an important influence on the design and operating conditions of the equipment. Understanding the size characteristics of the liquid film can help design more efficient reactors, separators and heat exchangers, and optimize operating parameters to ensure that the equipment operates in the best state. Therefore, it is necessary to accurately measure the thickness of the liquid film.

[0027] Liquid film thickness is usually measured by electrical methods. Based on electrical properties such as conductivity, resistivity or capacitance, the thickness of the liquid film is deduced by measuring the above physical parameters of the liquid film. This method has the advantages of non-invasiveness, real-time monitoring and high sensitivity. The electrical measurement method can measure without destroying the shape of the liquid film; the electrical method can realize online monitoring and is suitable for dynamic processes; the electrical method can detect tiny changes in liquid film thickness. The use of the electrical method to measure the thickness of the liquid film requires accurate calibration of the liquid film thickness measuring instrument. The calibration process is: select a series of liquid samples with known thickness and conductivity, keep the environmental conditions stable, use standard liquids of known thickness for measurement, and record the instrument readings. Use standard liquids of different concentrations and thicknesses for measurement in turn, and record the instrument readings and corresponding standard thicknesses for each measurement. Finally, all measurement results are summarized to form a calibration data set. Use the calibrated liquid film thickness measuring instrument to carry out measurements, and compare the measurement results with the calibration data set to obtain the measured liquid film thickness.

[0028] Patent CN109724508B discloses a calibration device for a conductivity-based liquid film thickness meter, but the device can only calibrate the liquid film thickness meter under normal temperature and pressure conditions. Under actual working conditions, the liquid film thickness meter often needs to measure the liquid film thickness under high temperature and high pressure scenarios, and the existing devices cannot work normally under high temperature and high pressure conditions. The calibration devices used in some technical solutions also include large-volume components such as micrometers and micrometers, which makes it difficult to directly install the calibration device into a pressure vessel for testing. At the same time, the thermal deformation of the calibration device itself under high temperature and high pressure conditions will also cause errors in the calibration results, which is not conducive to improving the accuracy of the liquid film thickness meter.

[0029] To solve the above problems, an embodiment of one aspect of the present invention provides a calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions. The structure of the device is as Figure 1 shown, and it includes a pressure vessel 1, a calibration platform 3, a nitrogen cylinder 10 as a pressurizing device, and a heating module 2. Among them, the calibration platform 3 and the heating module 2 are arranged inside the pressure vessel 1; the nitrogen cylinder 10 is connected to the pressure vessel 1, and the high-pressure nitrogen in the nitrogen cylinder 10 forms a high-pressure environment inside the pressure vessel 1; a standard solution is accommodated in the pressure vessel 1, and the physical parameters of the standard solution under different temperature and pressure conditions are known, and the calibration platform 3 is immersed in the standard solution. The calibration platform 3 includes a first clamping plate 16 arranged below and a second clamping plate 17 arranged above. The first clamping plate 16 and the second clamping plate 17 at least partially overlap each other in the vertical direction and form a clamping plate gap, and a standard solution liquid film is formed in the clamping plate gap; the first clamping plate 16 and the second clamping plate 17 are made of alumina ceramic material, and the alumina ceramic material has an extremely low coefficient of thermal expansion (only 5×10 -6 -8×10 -6 / °C), and at the same time has good chemical stability, which can ensure the structural stability and dimensional stability under high temperature and high pressure conditions. The heating module 2 is used to heat the standard solution to make the calibration environment reach the specified temperature.

[0030] The pressure vessel 1 is integrally cylindrical, with a top cover 18 at the top. The top cover 18 is fixedly connected to the wall of the pressure vessel 1 through a flange 11, so that the whole pressure vessel 1 can withstand a pressure of at least 6 MPa. An interface for a pressure regulating pipeline 8 and a water inlet 12 are provided on the top cover 18. The nitrogen cylinder 10 is connected to the inside of the pressure vessel 1 through the pressure regulating pipeline 8, and the air pressure can be adjusted through a pressure regulating valve 9; the water inlet 12 is used to inject the standard solution into the pressure vessel 1. A water outlet 13 is provided at the bottom of the pressure vessel 1 for discharging the standard solution in the pressure vessel 1. A measuring instrument replacement channel 7 is provided on the side wall of the pressure vessel 1. The measuring instrument replacement channel 7 is closed by a pressure valve or a pressure-bearing plug fixed by a flange under normal working conditions, and is opened when the calibration platform 3 needs to be set before the test to reduce the workload during the replacement process.

[0031] Specifically, a through mounting hole is provided in the middle of the first clamping plate 16, and the liquid film thickness measuring instrument 5 to be calibrated is arranged in the mounting hole to measure the liquid film of the standard solution in the clamping plate gap between the first clamping plate 16 and the second clamping plate 17. The signal acquisition data line is led out from the liquid film thickness measuring instrument and passes through the reserved data line channel on the top cover 18 of the pressure vessel 1 to be signal-connected to the upper computer 15, so as to output and display the measurement signal of the liquid film thickness measuring instrument 5 on the upper computer 15, which is processed and output by the upper computer 15. In other embodiments, according to the different mechanical structures and measurement principles of different liquid film thickness measuring instruments 5, the fixing structure and installation relationship between the first clamping plate 16, the second clamping plate 17 and the liquid film thickness measuring instrument 5 can be adjusted adaptively.

[0032] In different embodiments, the first clamping plate 16 and the second clamping plate 17 can adopt different structures. In some embodiments, the first clamping plate 16 and the second clamping plate 17 can be set as an integral structure, jointly forming an integral clamping plate and fixed on the bracket 14. The size of the clamping plate gap between the first clamping plate 16 and the second clamping plate 17 is fixed. During calibration, the measurement of the calibration data set is realized by replacing the integral clamping plate with different clamping plate gaps as a whole.

[0033] In other embodiments, the width of the clamping plate gap between the first clamping plate 16 and the second clamping plate 17 is set to be adjustable, and different clamping plate gap widths are formed by the adjusting device without replacing the first clamping plate 16 and the second clamping plate 17. In a preferred embodiment, an adjusting bolt 4 is arranged between the first clamping plate 16 and the second clamping plate 17. When the adjusting bolt 4 is rotated, the adjusting bolt 4 is axially relatively fixed to one of the first clamping plate 16 or the second clamping plate 17. By rotating the adjusting bolt 4, the clamping plate spacing between the first clamping plate 16 and the second clamping plate 17 is adjusted according to the thread pitch of the adjusting bolt 4. Specifically, the adjusting bolts 4 are uniformly arranged along the circumferences of the first clamping plate 16 and the second clamping plate 17 to ensure that the clamping plate gaps are uniform, and can be set to 3, 4 or more. The adjusting bolt 4 can also be made of a material with an extremely low coefficient of thermal expansion, such as alumina ceramic material, to further improve the calibration accuracy. In other embodiments, the clamping plate gap between the first clamping plate 16 and the second clamping plate 17 can also be adjusted in other ways. For example, an alumina ceramic wedge with a scale can be inserted between the first clamping plate 16 and the second clamping plate 17, and the size of the clamping plate spacing is the thickness of the alumina ceramic wedge inserted between the first clamping plate 16 and the second clamping plate 17.

[0034] In different embodiments, for the technical solution with an adjustable clamping gap between the first clamping plate 16 and the second clamping plate 17, the first clamping plate 16 and the second clamping plate 17 can be set as an integral structure or as independent parts. When the first clamping plate 16 and the second clamping plate 17 are set as an integral structure, the adjustment range of the clamping gap is small to ensure that the deformation amounts of the first clamping plate 16 and the second clamping plate 17 do not exceed the elastic limit of the alumina ceramic material; when the first clamping plate 16 and the second clamping plate 17 are set as independent parts, the clamping gap can be adjusted in a relatively large range.

[0035] In a preferred embodiment, the heating module 2 is arranged below the calibration platform 3 so as to achieve a uniform temperature distribution through the convective heat transfer of the standard solution and improve the temperature control accuracy during the calibration process.

[0036] According to an embodiment of another aspect of the present invention, there is provided a calibration method for a liquid film thickness measuring instrument under high temperature and high pressure conditions. This method uses the calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions provided in any of the foregoing embodiments to calibrate the liquid film thickness measuring instrument to be calibrated. In a preferred embodiment, the liquid film thickness measuring instrument to be calibrated is configured as an electrical liquid film thickness measuring instrument.

[0037] In a preferred embodiment, the calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions as shown in Figure 1 is used to calibrate the liquid film thickness measuring instrument 5. The liquid film thickness measuring instrument 5 is a resistive liquid film thickness measuring instrument; the first clamping plate 16 and the second clamping plate 17 are set as a split structure, and the distance is adjusted by the adjusting bolt 4. The specific method is as follows:

[0038] Step a): Provide a standard solution, the composition of the standard solution is the same as the solution to be measured under the actual working conditions of the liquid film thickness measuring instrument 5, measure the electrophysical parameters of the standard solution under the specified temperature (275 °C) and pressure (6 MPa) conditions, and determine the quantity and data distribution of the calibration data set to be established according to the design parameters of the liquid film thickness measuring instrument 5.

[0039] Step b): Open the measuring instrument replacement channel 7, fixedly install the liquid film thickness measuring instrument 5 on the first clamping plate 16, and rotate the adjusting bolt 4 according to the data distribution to adjust the distance between the second clamping plate 17 and the first clamping plate 16 to the first measured value.

[0040] Step c): Close the pressure vessel 1, inject the standard solution from the water inlet 12 until it submerges the calibration platform 3, adjust the pressure in the pressure vessel 1 to 6 MPa through the pressure regulating valve 9, heat the standard solution to 275 °C by using the heating module 2, measure by using the liquid film thickness measuring instrument 5, and record the data output by the upper computer 15. Specifically, the heating module 2 can be set as an electric heating rod.

[0041] Step d): Next, relieve the pressure of the pressure vessel 1, and discharge the standard solution in the pressure vessel 1 from the water outlet 13.

[0042] Step e): Rotate the adjusting bolt 4 according to the requirements for establishing the calibration data set, adjust the distance between the second clamping plate 17 and the first clamping plate 16 to the next measured value, and repeat steps b) to d) until all the measurements of the calibration data set are completed, thus completing the calibration of the liquid film thickness measuring instrument.

[0043] Subsequently, this liquid film thickness measuring instrument can be used to measure the liquid film thickness of the standard solution at 6 MPa and 275°C.

[0044] The purpose of the above embodiments is to further elaborate on the present invention with reference to the accompanying drawings, so that those skilled in the art can understand the technical concept of the present invention. Within the scope disclosed by the present invention, optimizing or equivalently replacing the component structures or method steps involved, and combining the implementation manners in different embodiments without conflict in structure and principle all fall within the protection scope of the present invention.

Claims

1. A calibration device for a liquid film thickness measuring instrument under high temperature and high pressure conditions, characterized in that, It includes a pressure vessel, a calibration platform, a pressurizing device and a heating module; Among them, the calibration platform and the heating module are arranged inside the pressure vessel. The pressurizing device is connected to the pressure vessel and forms a pressure environment inside the pressure vessel. A standard solution is contained inside the pressure vessel, and the standard solution submerges the calibration platform; The calibration platform includes a first clamping plate and a second clamping plate made of alumina ceramics. The first clamping plate and the second clamping plate at least partially overlap each other in the vertical direction. A clamping plate gap is formed in the overlapping area of the first clamping plate and the second clamping plate, and a standard solution liquid film is formed in the clamping plate gap; The heating module is used to heat the standard solution.

2. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1, wherein, The width of the clamping plate gap is set to be adjustable.

3. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 2, wherein, An adjusting bolt is arranged between the first clamping plate and the second clamping plate, and the clamping plate gap is adjusted by rotating the adjusting bolt.

4. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1 or 2 or 3, characterized in that, The first clamping plate and the second clamping plate are arranged as independent parts.

5. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1 or 2 or 3, characterized in that, The pressurizing device is configured as a high-pressure gas cylinder.

6. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1 or 2 or 3, characterized in that, The heating module is configured as an electric heating device, and the heating module is arranged below the calibration platform.

7. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1 or 2 or 3, characterized in that, A through data line channel is arranged on the pressure vessel to allow the data line to extend from inside the pressure vessel to outside the pressure vessel.

8. The calibration device for the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 1 or 2 or 3, characterized in that, The first clamping plate is arranged below the second clamping plate, and a through mounting hole is arranged on the first clamping plate. The mounting hole is used to mount the liquid film thickness measuring instrument to be calibrated.

9. A calibration method for a liquid film thickness measuring instrument under high temperature and high pressure conditions, characterized in that, The liquid film thickness measuring instrument to be calibrated is calibrated by using the liquid film thickness measuring instrument calibration device under high temperature and high pressure conditions as described in any one of claims 1 to 8.

10. The calibration method of the liquid film thickness measuring instrument under high temperature and high pressure conditions according to claim 9, characterized in that, The liquid film thickness measuring instrument to be calibrated is configured as an electrical liquid film thickness measuring instrument.

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