Three-section capacitive LNG (Liquefied Natural Gas) liquid level sensor

Abstract

The utility model relates to a three-section capacitance type LNG liquid level sensor which comprises an outer metal pipe, three inner metal pipes, an inner pipe connecting piece, an end socket and a bottom supporting piece, the three inner metal pipes are all located in the outer metal pipe and are coaxially arranged with the outer metal pipe, the end socket is connected with the top of the outer metal pipe, the bottom supporting piece is connected with the lower end of the outer metal pipe, and the inner pipe connecting piece is connected with the end socket. Every two adjacent inner metal pipes are connected through an inner pipe connecting piece, each inner pipe connecting piece comprises a connecting pipe, a limiting baffle and a partition plate, the connecting pipes are used for allowing the two adjacent inner metal pipes to be connected in an inserted mode, the limiting baffles are arranged on the outer walls of the connecting pipes and used for allowing the inner metal pipes to abut against, and the partition plates are arranged in the connecting pipes. The partition plate is provided with three wire passing holes for wires to pass through, and the three wire passing holes are arranged at intervals. According to the utility model, the lead is prevented from being exposed in the LNG liquid, the service life of the lead is prolonged, and the assembly is convenient.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a three-segment capacitive LNG level sensor. Background Technology

[0002] In modern industrial production, instruments and meters are crucial tools for monitoring equipment operation, and level gauges, as instruments for measuring the level of liquid media in containers, play an irreplaceable role. Currently, level gauges are mainly classified into magnetic levitation, pressure, and ultrasonic types, but these types often suffer from insufficient measurement accuracy, complex structures, and high prices, falling far short of meeting the needs of modern industrial production. Therefore, in recent years, a new type of capacitive level gauge has emerged. The working principle of a capacitive level gauge is to convert the positional change of the measured object into capacitance for measurement. This type of level gauge has advantages such as high resolution and fast dynamic response.

[0003] With the increasing popularity of capacitive level gauges, there is a growing demand for measuring the level of cryogenic solutions (medium temperature > -200℃) such as liquid nitrogen and LNG in low-pressure environments (<2.5MPa), especially in LNG storage tank applications. However, due to differences in the dielectric constant of LNG at various refueling stations across the country, and the change in the dielectric constant of the gas caused by temperature variations within the tank, the capacitance increment measured by the level gauge varies, resulting in inaccurate LNG level readings. In such cases, recalibration at a service station based on the actual dielectric constant is required, which is time-consuming and labor-intensive. To address this issue, some three-stage capacitive level gauges have emerged. When the LNG level exceeds the lower stage of the gauge, the capacitance of the LNG level can be calculated based on the capacitance of the lower stage. The dielectric constant of the gas inside the storage tank can be calculated based on the capacitance of the upper section of the LNG level gauge, thus allowing for real-time updates to the dielectric constant of the LNG liquid and ensuring the accuracy of the LNG level display. However, the three-section capacitive level gauge currently used in LNG storage tanks requires the inner tube to be set into three sections during actual production. Adjacent inner tubes need to be connected together. Since each section of the inner tube requires an independent wire to be connected to the circuit of the capacitive level gauge, the wires of each section need to be placed between the inner and outer tubes. This not only makes assembly inconvenient but also easily leads to the wires being exposed to the LNG liquid, reducing the service life of the wires. Utility Model Content

[0004] The purpose of this invention is to provide a three-segment capacitive LNG level sensor to solve the aforementioned problems of current three-segment capacitive LNG level sensors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A three-segment capacitive LNG level sensor includes an outer metal tube, an inner metal tube, an inner tube connector, an end cap, and a bottom support. Three inner metal tubes are provided, all located within the outer metal tube and coaxially arranged with it. The end cap is connected to the top of the outer metal tube, and the bottom support is connected to the lower end of the outer metal tube. Adjacent inner metal tubes are connected via the inner tube connector. The inner tube connector includes a connecting pipe, a limiting baffle, and a partition plate. The connecting pipe allows adjacent inner metal tubes to be inserted into each other. The limiting baffle is located on the outer wall of the connecting pipe for the inner metal tubes to abut against. The partition plate is located inside the connecting pipe and has three wire-passing holes spaced apart.

[0007] Furthermore, the partition plate is provided with wire clamping connectors on both sides of the wire passage hole, and the wires passing through the wire passage hole are clamped by the wire clamping connectors.

[0008] Furthermore, an arc-shaped plate is provided on the limiting baffle extending outward along the radial direction of the connecting pipe. Multiple arc-shaped plates are provided circumferentially. The arc-shaped plates abut against the inner wall of the outer metal pipe to achieve the coaxial arrangement of the outer metal pipe and the inner metal pipe.

[0009] Furthermore, the bottom support includes a support column, which is provided with an insertion step for inserting the outer metal tube and an insertion groove for inserting the inner metal tube. The top surface of the support column is provided with a plurality of first liquid inlet holes, which are closed at the lower end and open at the upper end to communicate the gap between the inner metal tube and the outer metal tube. The side wall of the support column is provided with a plurality of second liquid inlet holes in the radial direction, which communicate with the first liquid inlet holes.

[0010] Furthermore, a wire fixing part is provided inside the end.

[0011] Furthermore, the wire fixing part includes a fixing plate and screws, the wires are arranged side by side inside the end, the fixing plate is pressed on each of the wires, and is fixedly connected to the end by the screws.

[0012] The beneficial effects of this utility model are:

[0013] This utility model discloses a three-segment capacitive LNG level sensor. Through its three-segment inner metal tube design, combined with a partition plate and wire-passing hole structure in the inner tube connector, it can accurately distinguish and measure the capacitance changes at different liquid levels in an LNG storage tank, thereby accurately calculating the LNG level. This solves the measurement error problem caused by changes in dielectric constant, improving the accuracy and reliability of level measurement. The partition plate in the inner tube connector not only separates the inner metal tube but also provides an orderly passage for the wires through its wire-passing holes. This avoids direct exposure of the wires to the LNG liquid, reducing the risk of wire damage, extending the wire's service life, and improving the overall durability of the level sensor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the three-segment capacitive LNG level sensor of this utility model;

[0015] Figure 2 This is a schematic diagram of the inner metal tube in the three-segment capacitive LNG level sensor of this utility model;

[0016] Figure 3 This is a schematic diagram of the inner tube connector in the three-segment capacitive LNG level sensor of this utility model;

[0017] Figure 4 This is a schematic diagram of the bottom support component in the three-segment capacitive LNG level sensor of this utility model;

[0018] Figure 5 This is a schematic diagram of the structure of the end of the three-segment capacitive LNG level sensor of this utility model.

[0019] The names corresponding to each mark in the diagram:

[0020] 1. Outer metal tube,

[0021] 2. Inner metal tube,

[0022] 3. Inner pipe connectors,

[0023] 31. Connecting pipe,

[0024] 32. Limit baffle,

[0025] 321. Curved plate,

[0026] 33. Partition board,

[0027] 331. Wire guide hole,

[0028] 332. Wire clamp connector,

[0029] 4. End,

[0030] 5. Bottom support components,

[0031] 51. Support column,

[0032] 52. Insert step,

[0033] 53. Insertion groove,

[0034] 54. First liquid inlet hole,

[0035] 55. Second liquid inlet,

[0036] 6. Wire fixing part,

[0037] 61. Fixing plate,

[0038] 62. Screw. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0040] Example 1

[0041] like Figures 1 to 5 As shown, a three-segment capacitive LNG level sensor includes an outer metal tube 1, an inner metal tube 2, an inner tube connector 3, an end cap 4, and a bottom support 5. Three inner metal tubes 2 are provided, all located within the outer metal tube 1 and coaxially arranged with it. The end cap 4 is connected to the top of the outer metal tube 1, and the bottom support 5 is connected to the lower end of the outer metal tube 1. Adjacent inner metal tubes 2 are connected by the inner tube connector 3 to achieve connection between the inner metal tubes 2.

[0042] Specifically, the inner tube connector 3 includes a connecting tube 31, a limiting baffle 32, and a partition plate 33. The connecting tube 31 is used for insertion of two adjacent inner metal tubes 2 to achieve connection between the two adjacent inner metal tubes 2. The limiting baffle 32 is disposed on the outer wall of the connecting tube 31 and is used for the inner metal tube 2 to abut against, thereby restricting the position of the inner metal tube 2 within the connecting tube 31. The partition plate 33 is disposed within the connecting tube 31 and is provided with three wire-passing holes 331 for wires to pass through. The three wire-passing holes 331 are spaced apart to avoid mutual interference between the wires of different inner metal tubes 2, while ensuring that the wires of each inner metal tube 2 can pass through in an orderly manner and connect to the circuit part of the capacitive level gauge.

[0043] Example 2

[0044] like Figure 3As shown, the difference between this embodiment and embodiment 1 is that wire clamping connectors 332 are provided on both sides of the wire hole 331 on the partition plate 33. The wire clamping connectors 332 are used to clamp the wires passing through the wire hole 331 to further fix the wires and prevent the wires from shaking or coming out in the wire hole 331.

[0045] Example 3

[0046] like Figure 2 and Figure 3 As shown, the difference between this embodiment and embodiment 1 or embodiment 2 is that an arc-shaped plate 321 is provided on the limiting baffle 32 extending outward along the radial direction of the connecting pipe 31. Multiple arc-shaped plates 321 are arranged circumferentially. The arc-shaped plates 321 abut against the inner wall of the outer metal pipe 1 to achieve the coaxial arrangement of the outer metal pipe 1 and the inner metal pipe 2, thereby ensuring the accuracy of liquid level measurement.

[0047] Example 4

[0048] like Figure 1 and Figure 4 As shown, the difference between this embodiment and any of embodiments 1 to 3 is that the bottom support 5 includes a support column 51. The support column 51 is provided with an insertion step 52 for inserting the outer metal tube 1 and an insertion groove 53 for inserting the inner metal tube 2, so as to achieve stable installation of the outer metal tube 1 and the inner metal tube 2 on the bottom support 5. The top surface of the support column 51 is provided with a plurality of first liquid inlet holes 54. The lower end of the first liquid inlet hole 54 is closed and the upper end is open, so as to connect the gap between the inner metal tube 2 and the outer metal tube 1, so that LNG liquid can smoothly enter the gap between the inner metal tube 2 and the outer metal tube 1. The side wall of the support column 51 is provided with a plurality of second liquid inlet holes 55 in the radial direction. The second liquid inlet holes 55 are connected to the first liquid inlet holes 54 to ensure the accuracy of measurement.

[0049] Example 5

[0050] like Figure 1 and Figure 5 As shown, the difference between this embodiment and any of the embodiments 1 to 4 is that a wire fixing part 6 is provided inside the end 4 to fix the wire passing through the inner metal tube 2 and prevent the wire from shaking or coming out inside the end 4.

[0051] Specifically, the wire fixing part 6 includes a fixing plate 61 and screws 62. The wires are arranged side by side inside the end 4, the fixing plate 61 is pressed on each wire, and fixedly connected to the end 4 by screws 62 to achieve stable fixing of the wires.

[0052] This utility model discloses a three-segment capacitive LNG level sensor. By incorporating an inner tube connector 3, it achieves connection between adjacent inner metal tubes 2. Simultaneously, by providing wire-passing holes 331 on the partition plate 33, the wires of each inner metal tube 2 can be orderly passed through and connected to the circuitry of the capacitive level sensor, preventing the wires from being exposed to the LNG liquid, thus extending the service life of the wires and facilitating assembly. Furthermore, by incorporating a wire clamping connector 332, an arc-shaped plate 321, a first inlet hole 54, a second inlet hole 55, and a wire fixing part 6, the stability and reliability of the level sensor are further improved, ensuring accurate measurement of the LNG level.

[0053] Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model are within the protection scope of this utility model.

Claims

1. A three-segment capacitive LNG level sensor, characterized in that: The device includes an outer metal tube, inner metal tubes, inner tube connectors, end caps, and a bottom support. Three inner metal tubes are provided, all located within the outer metal tube and coaxially arranged with it. The end caps are connected to the top of the outer metal tubes, and the bottom support is connected to the lower end of the outer metal tubes. Adjacent inner metal tubes are connected by the inner tube connectors. Each inner tube connector includes a connecting pipe, a limiting baffle, and a partition plate. The connecting pipe allows adjacent inner metal tubes to be inserted into each other. The limiting baffle is located on the outer wall of the connecting pipe for the inner metal tubes to abut against. The partition plate is located inside the connecting pipe and has three wire-passing holes spaced apart.

2. The three-segment capacitive LNG level sensor according to claim 1, characterized in that: The partition plate is provided with wire clamps on both sides of the wire passage hole, and the wires passing through the wire passage hole are clamped by the wire clamps.

3. The three-segment capacitive LNG level sensor according to claim 2, characterized in that: An arc-shaped plate extends outward along the radial direction of the connecting pipe on the limiting baffle. Multiple arc-shaped plates are arranged circumferentially. The arc-shaped plates abut against the inner wall of the outer metal pipe to achieve coaxial arrangement of the outer metal pipe and the inner metal pipe.

4. The three-segment capacitive LNG level sensor according to claim 1, characterized in that: The bottom support includes a support column, which has an insertion step for inserting the outer metal tube and an insertion groove for inserting the inner metal tube. The top surface of the support column has a plurality of first liquid inlet holes, which are closed at the lower end and open at the upper end to communicate the gap between the inner metal tube and the outer metal tube. The side wall of the support column has a plurality of second liquid inlet holes arranged radially inward, which communicate with the first liquid inlet holes.

5. The three-segment capacitive LNG level sensor according to claim 1, characterized in that: The end is provided with a wire fixing part.

6. The three-segment capacitive LNG level sensor according to claim 5, characterized in that: The wire fixing part includes a fixing plate and screws. The wires are arranged side by side inside the end. The fixing plate is pressed on each of the wires and fixedly connected to the end by the screws.

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