A high-pressure container liquid level detection method based on normal-pressure instruments

Abstract

The application provides a high-pressure container liquid level detection method based on a normal-pressure instrument, and belongs to the technical field of liquid level detection.The high-pressure container liquid level detection method based on the normal-pressure instrument comprises the following steps: a transparent pressure-isolating cover plate is designed; a measurement channel is arranged on the high-pressure container; a sensor fixing plate is designed; the sensor fixing plate is installed on the high-pressure container; the pressure-isolating cover plate is installed on the sensor fixing plate; a laser distance measuring sensor is placed on the pressure-isolating cover plate; an instrument cover is installed outside the laser distance measuring sensor; and the laser distance measuring sensor is started to detect the liquid level in the high-pressure container.The high-pressure container liquid level detection method based on the normal-pressure instrument is simple to operate, low in cost, and can detect the liquid level of the high-pressure container by using a normal instrument in a normal-pressure environment.

Description

Technical Field

[0001] This invention belongs to the field of liquid level detection technology, specifically relating to a method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument. Background Technology

[0002] In production and daily life, high-pressure gas storage tanks are commonly used to store compressed gases such as liquefied petroleum gas (LPG), liquefied natural gas (LNG), and oxygen. Liquid level measurement is a crucial step in monitoring and controlling the height of the liquid or gas within the storage tank. The accuracy and stability of liquid level measurement are essential for the safe operation of the storage tank. Accurate monitoring of the liquid level in high-pressure gas storage tanks helps prevent overfilling or over-draining, avoiding abnormal increases or decreases in internal pressure, thus ensuring the safe operation of the storage tank. Simultaneously, in some industrial production processes, liquid level measurement in storage tanks can be used to monitor and control the supply of raw materials, ensuring the stability and continuity of the production process. For energy reserves such as LPG and LNG, liquid level measurement helps to monitor and manage the storage capacity in the tank in real time, ensuring the stability of the energy supply.

[0003] High-voltage measuring instruments are complex and costly, while conventional instruments are relatively simple and inexpensive, but they cannot function properly under high-voltage conditions. Firstly, measurements under high voltage require consideration of the impact of high voltage on the instrument's structure; high voltage places higher demands on the instrument's sealing performance, mechanical stability, and pressure resistance. Therefore, to ensure the normal operation of conventional instruments under high-voltage conditions, special sealing structures and materials must be used. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument. This invention aims to solve the problem that conventional liquid level measuring instruments are limited by high pressure and cannot directly measure the liquid level of high-pressure vessels.

[0005] To achieve the above objectives, the present invention provides a method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument, comprising the following steps:

[0006] S1. Design a transparent pressure-isolating cover plate based on optical performance and gas pressure inside the high-pressure vessel;

[0007] S2. A measuring channel is set on the high-pressure vessel, the measuring channel is perpendicular to the liquid surface inside the high-pressure vessel, and a float is installed in the measuring channel;

[0008] S3. Design the sensor mounting plate based on the measurement channel and the pressure isolation cover;

[0009] S4. Install the sensor mounting plate onto the high-pressure vessel using the flange and second bolts, with the center of the sensor mounting plate facing the measurement channel.

[0010] S5. Install the pressure-isolating cover plate onto the sensor mounting plate using the first bolt;

[0011] S6. Place a laser rangefinder on the pressure-isolating cover plate, with the pulse emitting end of the laser rangefinder facing the center of the measurement channel;

[0012] S7. Install an instrument cover on the outside of the laser rangefinder sensor;

[0013] S8. Activate the laser rangefinder sensor to detect the liquid level inside the high-pressure container.

[0014] Furthermore, step S1 includes the following sub-steps:

[0015] S1.1 Material selection for the pressure-absorbing cover;

[0016] The pressure-resistant cover is made of a material with high pressure resistance, high light transmittance, and low refractive index.

[0017] S1.2 Dimensional parameters design of the pressure-absorbing cover plate;

[0018] The pressure diaphragm cover plate is designed according to the standard flange with a diameter of d1. The pressure diaphragm cover plate has first bolt holes at both ends, with the diameter of the first bolt holes being d0 and the spacing between the first bolt holes being a0.

[0019] The thickness of the pressure-retaining cover plate is determined based on the gas pressure inside the high-pressure vessel, and the calculation expression is as follows:

[0020]

[0021] In the formula, δ p D represents the calculated thickness of the pressure relief cover. c [σ] represents the calculated diameter of the pressure diaphragm cover; p represents the design pressure of the pressure diaphragm cover; t φ represents the allowable stress of the pressure diaphragm material at the design temperature; K represents the weld coefficient;

[0022] The minimum thickness d of the pressure relief cover plate to meet the compressive strength is calculated based on equation (1). min Where the weld coefficient φ is 1, the structural characteristic coefficient K of the pressure diaphragm cover is 0.25, and d min The calculation expression is as follows:

[0023]

[0024] In the formula, P1 is the pressure inside the high-pressure vessel being tested; d1 is the diameter of the pressure diaphragm cover; and P2 is the allowable stress of the pressure diaphragm cover material at the design temperature.

[0025] Based on optical transmittance, the maximum thickness d of the pressure plate required for the laser sensor to operate normally is calculated. max The calculation expression is as follows:

[0026]

[0027] In the formula, T min α represents the minimum transmittance required for the pressure-blocking cover to function properly with the laser sensor; α represents the attenuation coefficient.

[0028] The thickness h0 of the pressure-reducing cover plate satisfies: d min ≤h0≤d max .

[0029] Furthermore, the transparent pressure-blocking cover is made of transparent polycarbonate sheet.

[0030] Furthermore, step S3 includes the following sub-steps:

[0031] Material selection for the S3.1 sensor mounting plate;

[0032] The sensor mounting plate is made of a material with high compressive strength;

[0033] S3.2 Sensor mounting plate shape design;

[0034] A through hole is reserved in the middle of the sensor mounting plate to facilitate liquid level detection by the laser rangefinder; the upper part of the sensor mounting plate adopts a sunken structure, and the sunken part is installed with a transparent pressure-isolating cover plate.

[0035] S3.3 Sensor Mounting Plate Dimensions Design;

[0036] Based on the dimensions of the pressure-isolating cover, the dimensions of the recessed sensor fixing plate structure are designed. The sensor fixing plate is provided with positioning holes at the positions corresponding to the bolt holes of the pressure-isolating cover, and the diameter of the positioning holes is d0.

[0037] The sensor mounting plate is designed according to the standard flange with a diameter of d4. The sensor mounting plate has second bolt holes at both ends, with a diameter of d2 and a spacing of a1 between the second bolt holes.

[0038] The thickness h2 of the sensor mounting plate is calculated according to formula (1);

[0039] h2≥d 2min (4)

[0040] In the formula, d 2min This indicates the thickness of the sensor mounting plate to meet the minimum compressive strength requirements.

[0041] Furthermore, the sensor mounting plate is made of nitrogen-strengthened austenitic stainless steel.

[0042] Furthermore, in step S3, d 2min The calculation expression is as follows:

[0043]

[0044]

[0045] In the formula, P1 is the pressure inside the high-pressure vessel being measured; d4 is the diameter of the sensor fixing plate; P2 is the allowable stress of nitrogen-strengthened austenitic stainless steel at the design temperature; the weld coefficient φ is 0.8; and the structural characteristic coefficient K of the pressure diaphragm cover is 0.25.

[0046] Furthermore, a sealing ring is provided between the pressure-isolating cover plate and the sensor fixing plate.

[0047] Furthermore, a first rubber gasket is also provided between the flange and the high-pressure vessel.

[0048] Furthermore, a second rubber gasket is provided between the sensor mounting plate and the flange.

[0049] The beneficial effects of this invention are as follows:

[0050] 1. This invention proposes a method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument. It is simple to operate and low in cost. The liquid level of the high-pressure vessel can be detected using a conventional instrument under atmospheric pressure. The method of this invention achieves non-contact measurement by designing a sensor fixing plate, a pressure isolation cover plate and a float. The measuring instrument is isolated from the high-pressure environment and always operates under atmospheric pressure. The liquid level is detected by reflecting the height of the float on the liquid level using a laser rangefinder sensor.

[0051] 2. This invention designs a pressure isolation structure between a high-pressure environment and a normal-pressure working area. To ensure that the laser rangefinder can transmit and receive light beams through the high-pressure isolation material, a combination of transparent pressure isolation material, sensor fixing plate, and measurement channel is adopted. At the same time, it ensures that the sensor will not be affected by displacement or vibration in the high-pressure environment and can work stably.

[0052] 3. This invention employs a measurement scheme adapted to high-pressure environments using conventional instruments, making it more widely applicable. This scheme can be used for high-pressure measurements in industrial production, energy management, scientific research, and other fields, meeting the needs of different industries. It is low-cost, easy to maintain and replace, thus saving resources and improving equipment utilization. The collected data is accurate, helping to monitor and control the production process in real time, avoiding overfilling or over-draining, and ensuring the safe operation of the equipment.

[0053] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0054] Figure 1 This is a schematic diagram illustrating the measurement principle of a high-pressure vessel liquid level detection method based on an atmospheric pressure instrument according to the present invention.

[0055] Figure 2 A cross-sectional view of the measuring pipes for a high-pressure vessel;

[0056] Figure 3 This is a schematic diagram showing the structural dimensions of the pressure-reducing cover plate;

[0057] Figure 4 A schematic diagram showing the structural dimensions of the sensor mounting plate;

[0058] The attached figures are labeled as follows: 1. High-pressure vessel; 2. Flange; 3. Sealing ring; 4. Pressure isolation cover; 5. Laser rangefinder sensor; 6. Instrument cover; 7. First bolt; 8. Second bolt; 9. Sensor mounting plate; 10. Second rubber gasket; 11. First rubber gasket; 12. Measuring pipe; 13. Buoy. Detailed Implementation

[0059] To make the technical solutions, advantages, and objectives of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of this application.

[0060] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0061] like Figure 1 and Figure 2 As shown, this invention provides a method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument, comprising the following steps:

[0062] S1. Based on the optical performance and the gas pressure inside the high-pressure container 1, design a transparent pressure-isolating cover plate 4;

[0063] Transparent materials can prevent particles or liquids in high-pressure environments from directly contacting or contaminating the optical components of the sensor, thereby maintaining the cleanliness and transparency of the optical components and ensuring the quality of laser beam transmission and reception.

[0064] Material selection for S1.1 pressure plate 4;

[0065] The pressure-isolating cover 4 is made of a material with strong pressure resistance, high light transmittance and low refractive index. In this embodiment, the material of the transparent pressure-isolating cover 4 is a transparent polycarbonate sheet.

[0066] S1.2 Design of the dimensional parameters of the pressure-isolating cover plate 4, such as Figure 3 As shown;

[0067] According to the standard flange design, the diameter of the pressure diaphragm cover plate 4 is d1. Both ends of the pressure diaphragm cover plate 4 are provided with first bolt holes, the diameter of the first bolt holes is d0, and the spacing between the first bolt holes is a0.

[0068] The thickness of the pressure-isolating cover plate 4 is determined based on the gas pressure inside the high-pressure vessel 1, and the calculation expression is as follows:

[0069]

[0070] In the formula, δ p D represents the calculated thickness of the pressure relief cover. c [σ] represents the calculated diameter of the pressure diaphragm cover; p represents the design pressure of the pressure diaphragm cover; t φ represents the allowable stress of the pressure diaphragm material at the design temperature; K represents the weld coefficient;

[0071] Based on equation (1), the minimum thickness d of the pressure-absorbing cover plate 4 to satisfy the compressive strength is calculated. min The weld coefficient φ is 1, the structural characteristic coefficient K of the pressure-absorbing cover plate 4 is 0.25, and d min The calculation expression is as follows:

[0072]

[0073] In the formula, P1 is the internal pressure of the high-pressure vessel 1 under test; d1 is the diameter of the pressure diaphragm cover plate 4; P2 is the allowable stress of the material of the pressure diaphragm cover plate 4 at the design temperature;

[0074] Based on the optical transmittance, the maximum thickness d of the pressure plate 4 is calculated to ensure the normal operation of the laser sensor. max The calculation expression is as follows:

[0075]

[0076] In the formula, T min The minimum transmittance required for the pressure-blocking cover 4 to ensure normal operation of the laser sensor; α represents the attenuation coefficient.

[0077] The thickness h0 of the pressure-reducing cover plate 4 satisfies: d min ≤h0≤d max .

[0078] S2. A measuring channel 12 is set on the high-pressure vessel 1. The measuring channel 12 is perpendicular to the liquid surface in the high-pressure vessel 1. A float is set in the measuring channel 12.

[0079] S3. Based on the measurement channel 12 and the pressure isolation cover plate 4, design the sensor fixing plate 9;

[0080] Material selection for S3.1 sensor mounting plate 9;

[0081] The sensor mounting plate 9 is made of a material with high compressive strength. In this embodiment, the material of the sensor mounting plate 9 is nitrogen-strengthened austenitic stainless steel.

[0082] The shape design of the S3.2 sensor mounting plate 9;

[0083] A through hole is reserved in the middle of the sensor mounting plate 9 to facilitate liquid level detection by the laser rangefinder; the upper part of the sensor mounting plate 9 adopts a sunken structure, and the sunken part is installed with a transparent pressure-isolating cover plate 4. The pressure-isolating cover plate 4 needs to be consistent with the size of the sunken structure of the sensor mounting plate 9.

[0084] The dimensional parameters of the S3.3 sensor mounting plate 9 are designed as follows: Figure 4 As shown;

[0085] Based on the size parameters of the pressure-isolating cover plate 4, the size parameters of the recessed structure of the sensor fixing plate 9 are designed. The sensor fixing plate 9 is provided with positioning holes at the positions corresponding to the bolt holes of the pressure-isolating cover plate 4, and the diameter of the positioning holes is d0.

[0086] The sensor mounting plate 9 is designed with a diameter of d4 according to the standard flange 2. The sensor mounting plate 9 has second bolt holes at both ends, with a diameter of d2 and a spacing of a1 between the second bolt holes.

[0087] The thickness h2 of the sensor fixing plate 9 is calculated according to formula (1);

[0088] h2≥d 2min (4)

[0089] In the formula, d 2min The thickness d represents the minimum compressive strength requirement for the sensor mounting plate 9. 2min The calculation expression is as follows:

[0090]

[0091]

[0092] In the formula, P1 is the internal pressure of the high-pressure vessel 1 under test; d4 is the diameter of the sensor fixing plate 9; P2 is the allowable stress of nitrogen-strengthened austenitic stainless steel at the design temperature; the weld coefficient φ is 0.8; and the structural characteristic coefficient K of the pressure diaphragm cover plate 4 is 0.25.

[0093] S4. The sensor mounting plate 9 is installed on the high-pressure vessel 1 by means of flange 2 and second bolt 8, with the center of sensor mounting plate 9 facing the measurement channel 12;

[0094] S5. Install the pressure isolation cover plate 4 onto the sensor fixing plate 9 using the first bolt 7;

[0095] S6. Place a laser rangefinder 5 on the pressure-isolating cover plate 4, with the pulse emitting end of the laser rangefinder 5 facing the center of the measurement channel 12;

[0096] S7. Install the instrument cover 6 outside the laser rangefinder sensor 5;

[0097] S8. Activate laser rangefinder 5 to detect the liquid level inside high-pressure container 1.

[0098] As a preferred embodiment, a sealing ring 3 is provided between the pressure isolation cover plate 4 and the sensor fixing plate 9.

[0099] As a preferred embodiment, a first rubber gasket 11 is provided between the flange 2 and the high-pressure vessel 1, and a second rubber gasket 10 is also provided between the sensor fixing plate 9 and the flange 2.

[0100] The detection principle of this invention is as follows: Figure 1 As shown: The pressure vessel contains the liquid to be tested. A measuring channel 12 is installed within the pressure vessel, and a float is placed inside the measuring channel 12. The float moves up and down with the liquid level, reflecting the liquid level in real time. A sensor mounting plate 9 is installed on the pressure vessel, and is fixedly connected to the pressure vessel via a flange 2 and a second bolt 8. A through hole is pre-drilled in the middle of the sensor mounting plate 9, facing the center of the measuring channel 12. The top of the sensor mounting plate 9 adopts a recessed structure, and a pressure isolation cover 4 is mounted on the sensor mounting plate 9 in a fitted manner via a first bolt 7. A laser rangefinder sensor 5 is placed in the center of the transparent pressure isolation cover 4. The pulse emitting end of the laser rangefinder sensor 5 faces the center of the measuring channel 12. The laser rangefinder sensor 5 emits pulses from the measuring channel 12 and receives echoes, achieving non-contact measurement and ensuring that the laser rangefinder sensor 5 operates normally under normal pressure, isolating the pressure vessel from the high-pressure environment. An instrument cover 6 is installed outside the sensors to ensure the normal operation of each sensor and to provide protection.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A method for detecting the liquid level in a high-pressure vessel based on an atmospheric pressure instrument, characterized in that, Includes the following steps: S1. Design a transparent pressure-isolating cover plate based on optical performance and gas pressure inside the high-pressure vessel; S1.1 Material selection for the pressure-absorbing cover plate; The pressure-resistant cover is made of a material with high pressure resistance, high light transmittance, and low refractive index. S1.2 Dimensional parameters design of the pressure-absorbing cover plate; The diameter of the pressure relief cover plate is designed according to the standard flange. The pressure-absorbing cover plate has first bolt holes at both ends, wherein the diameter of the first bolt holes is [missing information]. The spacing between the first bolt holes is ; The thickness of the pressure-retaining cover plate is determined based on the gas pressure inside the high-pressure vessel, and the calculation expression is as follows: In the formula, The calculated thickness of the pressure-reducing cover plate; This represents the calculated diameter of the pressure-reducing cover plate; This represents the design pressure of the pressure relief cover. This represents the allowable stress of the pressure diaphragm material at the design temperature. Represents the weld coefficient; Represents structural characteristic coefficients; The minimum thickness of the pressure diaphragm to meet the compressive strength requirement is calculated based on equation (1). Among them, the weld coefficient The structural characteristic coefficient of the pressure-absorbing cover is 1. It is 0.

25. The calculation expression is as follows: In the formula, The pressure inside the high-pressure vessel being measured; The diameter of the pressure-reducing cover plate; This refers to the allowable stress of the pressure-relief cover material at the design temperature. The maximum thickness of the pressure plate required to ensure normal operation of the laser sensor is calculated based on optical transmittance. The calculation expression is as follows: In the formula, This represents the minimum transmittance required for the pressure-blocking cover to ensure the normal operation of the laser sensor; Represents the attenuation coefficient; Thickness of the pressure plate satisfy: ; S2. A measuring channel is set on the high-pressure vessel, the measuring channel is perpendicular to the liquid surface inside the high-pressure vessel, and a float is installed in the measuring channel; S3. Design the sensor mounting plate based on the measurement channel and the pressure isolation cover; Material selection for the S3.1 sensor mounting plate; The sensor mounting plate is made of a material with high compressive strength; S3.2 Sensor mounting plate shape design; A through hole is reserved in the middle of the sensor mounting plate to facilitate liquid level detection by the laser rangefinder; the upper part of the sensor mounting plate adopts a sunken structure, and the sunken part is installed with a transparent pressure-isolating cover plate. S3.3 Sensor Mounting Plate Dimensions Design; Based on the dimensions of the pressure-isolating cover, the dimensions of the recessed sensor mounting plate structure are designed. The sensor mounting plate has positioning holes corresponding to the bolt holes of the pressure-isolating cover, and the diameter of the positioning holes is [missing information]. ; The sensor mounting plate diameter is designed according to the standard flange. The sensor mounting plate has second bolt holes at both ends, the diameter of which is... The spacing between the second bolt holes is ; The thickness of the sensor mounting plate is calculated according to equation (1). ; In the formula, The thickness of the sensor mounting plate represents the minimum compressive strength requirement. In step S3 The calculation expression is as follows: In the formula, The pressure inside the high-pressure vessel being measured; The diameter of the sensor mounting plate; Allowable stress of nitrogen-strengthened austenitic stainless steel at design temperature; weld coefficient The structural characteristic coefficient of the pressure diaphragm cover is 0.

8. It is 0.25; S4. Install the sensor mounting plate onto the high-pressure vessel using the flange and second bolts, with the center of the sensor mounting plate facing the measurement channel. S5. Install the pressure-isolating cover plate onto the sensor mounting plate using the first bolt; S6. Place a laser rangefinder on the pressure-isolating cover plate, with the pulse emitting end of the laser rangefinder facing the center of the measurement channel; S7. Install an instrument cover on the outside of the laser rangefinder sensor; S8. Activate the laser rangefinder sensor to detect the liquid level inside the high-pressure container.

2. The method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument according to claim 1, characterized in that: The pressure-isolating cover is made of transparent polycarbonate sheet.

3. The method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument according to claim 1, characterized in that: The sensor mounting plate is made of nitrogen-strengthened austenitic stainless steel.

4. The method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument according to claim 1, characterized in that: A sealing ring is provided between the pressure-isolating cover plate and the sensor fixing plate.

5. The method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument according to claim 1, characterized in that: A first rubber gasket is provided between the flange and the high-pressure vessel.

6. The method for detecting the liquid level of a high-pressure vessel based on an atmospheric pressure instrument according to claim 1, characterized in that: A second rubber gasket is provided between the sensor mounting plate and the flange.

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