Shielding structure of LNG (Liquefied Natural Gas) liquid level sensor

Abstract

The utility model relates to an LNG (Liquefied Natural Gas) liquid level sensor shielding structure which comprises an outer pipe, three leads, a shielding assembly and a lead fixing assembly, one end of each lead penetrates through the outer pipe and is arranged downwards, the other end of each lead penetrates out of the side wall of the outer pipe, and the shielding assembly is arranged in the outer pipe. Tubular bare terminals are connected to the positions, corresponding to the shielding assembly, of the three leads, the leads are sleeved with the tubular bare terminals, shielding layers are arranged on the leads and make contact with the tubular bare terminals, the tubular bare terminals are fixed in the outer tube through the shielding assembly, a metal fixing piece is arranged on the top of the outer tube, and the shielding assembly is connected with the metal fixing piece. According to the utility model, the precision and the anti-interference capability of the sensor are effectively improved, and the stability and the insulating property of the lead wire are ensured at the same time.

Description

TECHNICAL FIELD

[0001] The utility model relates to liquid level sensor technical field, concretely relates to a LNG liquid level sensor shielding structure. BACKGROUND

[0002] In modern industrial production, instruments and meters are important tools for detecting the operating conditions of equipment, and liquid level meters, as instruments for measuring the level of liquid medium in a container, play an irreplaceable role. Current liquid level meters are mainly divided into magnetic floating type, pressure type, ultrasonic type, etc. However, these types of liquid level meters have defects such as insufficient measurement accuracy, complex structure, high price, etc., and cannot meet the needs of modern industrial production. Therefore, in recent years, a new type of capacitive liquid level meter has emerged. The working principle of the capacitive liquid level meter is to convert the position change of the measured object into capacitance for measurement. This type of liquid level meter has the advantages of high resolution and fast dynamic response.

[0003] With the continuous popularity of capacitive liquid level meters, there is a demand for measuring the liquid level of low-temperature 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 the differences in the dielectric constant of LNG at liquid filling stations across the country, and the change in the dielectric constant of the gas in the storage tank when the temperature changes, the capacitance increment measured by the liquid level meter is different, resulting in inaccurate LNG liquid level. At this time, it is necessary to go to the service station to recalibrate according to the actual dielectric constant, which is time-consuming and labor-intensive. To solve the above problems, some three-section capacitive liquid level meters have emerged. When the LNG liquid exceeds the lower section of the liquid level meter, the dielectric constant of the LNG liquid at that time can be calculated according to the capacitance of the lower section, and the dielectric constant of the gas in the storage tank can be calculated according to the capacitance of the upper section of the LNG liquid level meter, so that the dielectric constant of the LNG liquid can be updated at any time, ensuring the accuracy of the LNG liquid level display. However, the three-section capacitive liquid level meter currently used in LNG storage tanks lacks grounding shielding for the lead, which affects the accuracy and anti-interference ability of the sensor. SUMMARY

[0004] The utility model aims at providing a LNG liquid level sensor shielding structure to solve the above problems of the current LNG liquid level sensor.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] The utility model provides a LNG liquid level sensor shielding structure, including outer tube, lead, shielding subassembly and lead fixed subassembly, the lead is provided with three, three the lead one end passes through the outer tube downward setting, the other end passes out the outer tube side wall setting, the shielding subassembly sets up in the outer tube, three the lead is on with the shielding subassembly corresponds to connect the pipe type bare terminal, each lead is set in the pipe type bare terminal, the lead has the shielding layer, the shielding layer with the pipe type bare terminal contact, the pipe type bare terminal is fixed in the outer tube through the shielding subassembly, the outer tube top is provided with metal fixed part, and the shielding subassembly is connected with the metal fixed part.

[0007] Further, the shielding subassembly includes a metal pressing plate and a screw, the metal pressing plate is provided with a clamping groove, the metal pressing plate is arranged on the metal fixed part, and the metal pressing plate is fixed to the metal fixed part by the screw, and the pipe type bare terminal is arranged in the clamping groove.

[0008] Further, the metal pressing plate and the metal fixed part are welded and fixed, and the screw and the metal pressing plate are welded and fixed.

[0009] Further, the outer tube is provided with a lead bundling assembly on the side wall, and each lead extends out of the side wall of the outer tube after passing through the lead bundling assembly.

[0010] Further, the lead bundling assembly includes a lead sleeve and a nut, the lead sleeve is arranged outwardly through the side wall of the outer tube, the lead sleeve is provided with each lead, and the nut is located outside the outer tube and is threadedly connected with the lead sleeve.

[0011] Further, the lead sleeve is provided with a tetrafluoro tube, and each lead is wrapped in the tetrafluoro tube.

[0012] The utility model discloses a LNG liquid level sensor shielding structure, through setting shielding subassembly, including metal pressing plate and screw, and with the pipe type bare terminal contact of lead shielding layer, has realized the effective shielding of lead.

[0013] The utility model discloses a LNG liquid level sensor shielding structure, through setting shielding subassembly, including metal pressing plate and screw, and with the pipe type bare terminal contact of lead shielding layer, has realized the effective shielding of lead.

[0014] Further, by setting the lead sleeve and the nut, each lead can pass out of the side wall of the outer tube in an orderly manner, and installation and debugging are facilitated. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of the lead wire;

[0016] Figure 2 This is a schematic diagram of the connection between the lead wire and the bare tube terminal;

[0017] Figure 3 This is a schematic diagram (three-dimensional view) of the shielding structure of the LNG level sensor of this utility model;

[0018] Figure 4 This is a front view of the shielding structure of the LNG level sensor of this utility model;

[0019] Figure 5 yes Figure 4 AA view.

[0020] The names corresponding to each mark in the diagram:

[0021] 1. Outer tube,

[0022] 2. Lead wire; 21. Sheath; 22. Shielding layer; 23. Insulation layer; 24. Conductor; 3. Tubular bare terminal.

[0023] 5. Metal fasteners,

[0024] 6. Metal pressure plate,

[0025] 7. Screws

[0026] 8. Card slot,

[0027] 9. Lead wire sleeve,

[0028] 10. Nuts

[0029] 11. PTFE tubing. Detailed Implementation

[0030] 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.

[0031] like Figures 1 to 5 As shown, the LNG level sensor shielding structure of this embodiment includes an outer tube 1, leads 2, a shielding assembly, and a lead fixing assembly. Three leads 2 are provided, with one end extending downwards through the outer tube 1 to connect to the measuring element (not shown) of the LNG level sensor, and the other end extending out of the side wall of the outer tube 1 to connect to an external circuit (not shown).

[0032] like Figure 1As shown, the cross-sectional structure of the lead used by the LNG liquid level sensor adopts a coaxial cable with a four-layer structure, from the outside to the inside, it is a sheath 21, a shielding layer 22, an insulating layer 23 and a conductor 24.

[0033] Figure 2 and Figure 3 As shown, the shielding assembly is arranged in the outer tube 1 for shielding the lead 2 to improve the accuracy and anti-interference ability of the sensor. Specifically, three leads 2 are respectively connected with pipe bare terminals 3 at positions corresponding to the shielding assembly. Each lead 2 is sleeved in the corresponding pipe bare terminal 3, and the shielding layer 22 on the lead 2 is in contact with the pipe bare terminal 3, thereby realizing the grounding of the shielding layer. The pipe bare terminal 3 is fixed in the outer tube 1 through the shielding assembly, ensuring the stability of the shielding effect.

[0034] Figure 4 and Figure 5 As shown, the top of the outer tube 1 is provided with a metal fixing piece 5, and the shielding assembly is connected with the metal fixing piece 5 to realize the fixation and grounding of the shielding assembly. Specifically, the shielding assembly includes a metal pressing plate 6 and a screw 7. The metal pressing plate 6 is provided with a clamping groove 8 for accommodating the pipe bare terminal 3. The metal pressing plate 6 is arranged on the metal fixing piece 5 and fixed on the metal fixing piece 5 through the screw 7, so as to firmly clamp the pipe bare terminal 3 in the clamping groove 8.

[0035] In order to improve the stability and grounding effect of the shielding assembly, the metal pressing plate 6 and the metal fixing piece 5 are fixed by welding, and the screw 7 and the metal pressing plate 6 are also fixed by welding. In this way, the entire shielding assembly forms a stable and well-conducting whole.

[0036] In addition, Figure 4 and Figure 5 As shown, the sidewall of the outer tube 1 is also provided with a lead bundling assembly for arranging and fixing the leads 2 passing through the sidewall of the outer tube 1. The lead bundling assembly includes a lead sleeve 9 and a nut 10. The lead sleeve 9 is arranged outside the sidewall of the outer tube 1, and the inside of the lead sleeve 9 is provided for each lead 2 to pass through. The nut 10 is located outside the outer tube 1 and is threadedly connected with the lead sleeve 9, so as to firmly fix the leads 2 in the lead sleeve 9.

[0037] The lead sleeve 9 is provided with a tetrafluoro tube 11, and each lead 2 is wrapped in the tetrafluoro tube 11, thereby effectively protecting the lead 2.

[0038] In summary, the shielding structure of the LNG liquid level sensor of the present embodiment effectively improves the accuracy and anti-interference ability of the sensor by arranging the shielding assembly and the lead bundling assembly, while ensuring the stability and insulation performance of the leads 2. This structure is particularly suitable for liquid level measurement in low-pressure and low-temperature environments such as LNG storage tanks, and can meet the requirements of modern industrial production for high precision and stability of liquid level meters.

[0039] Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

Claims

1. An LNG level sensor shield structure, characterized by: The utility model provides a kind of cable, including outer tube, lead, shielding assembly and lead fixing assembly, the lead is provided with three, three the lead one end passes through the outer tube and is set down, the other end passes out the outer tube side wall and is set, the shielding assembly is set in the outer tube, three the lead is connected with tube bare terminal on the place corresponding with the shielding assembly, each the lead is set in the tube bare terminal, the lead has shielding layer, the shielding layer is in contact with the tube bare terminal, the tube bare terminal is fixed in the outer tube by the shielding assembly, the outer tube top is provided with metal fixing piece, and the shielding assembly is connected with the metal fixing piece.

2. The LNG level sensor shield structure of claim 1, wherein: The shielding assembly includes a metal pressing plate and a screw, the metal pressing plate is provided with a clamping groove, the metal pressing plate is arranged on the metal fixing piece, and the metal pressing plate is fixed to the metal fixing piece by the screw, and the tube bare terminal is arranged in the clamping groove.

3. The LNG level sensor shield structure of claim 2, wherein: The metal pressing plate and the metal fixing piece are welded and fixed, and the screw and the metal pressing plate are welded and fixed.

4. The LNG level sensor shield structure of claim 3, wherein: The outer tube is provided with a lead bundling assembly on the side wall, and each lead extends out of the side wall of the outer tube after passing through the lead bundling assembly.

5. The LNG level sensor shield structure of claim 4, wherein: The lead bundling assembly includes a lead sleeve and a nut, the lead sleeve is arranged outwardly through the side wall of the outer tube, each lead is arranged to pass out of the lead sleeve, and the nut is located outside the outer tube and is threadedly connected with the lead sleeve.

6. The LNG level sensor shield structure of claim 5, wherein: The lead sleeve is provided with a PTFE tube, and each lead is wrapped in the PTFE tube.

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