A marine LNG sampling probe, a marine LNG sampling system, and a type testing and certification method

Abstract

This invention relates to the field of liquefied natural gas (LNG) testing technology, and discloses a marine LNG sampling probe, a marine LNG sampling system, and a type testing and certification method. The marine LNG sampling probe comprises an inner sampling tube, a vaporizer, a flexible connecting tube, and a vacuum outer tube. The inlet end of the inner sampling tube extends into the LNG main pipe; the vaporizer is connected to the outlet end of the inner sampling tube; the flexible connecting tube and the vacuum outer tube are both sleeved on the outside of the inner sampling tube; one end of the flexible connecting tube is connected to the vaporizer, and the other end is connected to the vacuum outer tube; the vacuum outer tube is installed to the LNG main pipe. By adding a flexible connecting tube between the vacuum outer tube and the vaporizer, the vertical impact and vibration generated during equipment operation can be effectively absorbed, thereby improving the overall vibration resistance of the probe. This solves the problem that traditional marine LNG sampling probes, due to excessive structural rigidity and insufficient vibration resistance design, are prone to fatigue damage under continuous vibration environments, thus ensuring the safety and long-term reliability of the entire sampling system.

Description

Technical Field

[0001] This invention relates to the field of liquefied natural gas (LNG) testing technology, and in particular to a marine LNG sampling probe, a marine LNG sampling system, and a type testing and certification method. Background Technology

[0002] Marine liquefied natural gas (LNG) sampling systems are critical equipment for monitoring the quality and quantity of ship fuel, and are typically installed in open deck areas subject to significant vibration. These systems must ensure measurement accuracy while also meeting stringent environmental adaptability, explosion-proof safety requirements, and complying with the technical specifications of major classification societies.

[0003] Currently, this field faces significant challenges at the equipment level. Traditional marine LNG sampling probes mainly consist of an inner sampling tube, a vacuum outer tube, a vaporizer, and a shut-off valve. The inlet end of the inner sampling tube is connected to the LNG sampling main pipe via a pipeline interface flange, used to extract LNG samples from the pipeline; the vaporizer is connected to the outlet end of the inner sampling tube, responsible for vaporizing the delivered LNG sample; the vacuum outer tube is fitted outside the inner sampling tube between the pipeline interface flange and the vaporizer, maintaining a vacuum inside to create an insulating space; the shut-off valve is installed on the inner sampling tube to control the pipeline's on / off state. However, existing traditional marine LNG sampling probes have a rigid structure and insufficient vibration resistance design, making them prone to fatigue damage under the continuous vibration environment of a ship, thus affecting the safety and service life of the entire sampling system.

[0004] Therefore, improving the vibration resistance of traditional marine LNG sampling probes has become a pressing technical problem that the industry needs to solve. Summary of the Invention

[0005] This invention provides a marine LNG sampling probe, a marine LNG sampling system, and a type testing and certification method to solve the problem of weak vibration resistance of traditional marine LNG sampling probes.

[0006] The first aspect of this invention provides a marine LNG sampling probe, comprising: The sampling inner tube has its inlet end inserted into the LNG main pipe for extracting LNG samples. A vaporizer is connected to the outlet end of the sampling inner tube; A flexible connecting tube is sleeved on the outside of the sampling inner tube; one end of the flexible connecting tube is connected to the vaporizer; A vacuum outer tube is fitted over the outside of the sampling inner tube; one end of the vacuum outer tube is connected to the other end of the elastic connecting tube, and the other end of the vacuum outer tube is used to install to the LNG main pipe.

[0007] The marine LNG sampling probe provided by the present invention further includes a fixing base; the fixing base includes: A fixed flange is provided, and the other end of the vacuum outer tube is used to connect to the pipeline flange of the LNG main pipe through the fixed flange; along the axial direction of the sampling inner tube, a first inner tube through hole is provided on the fixed flange, and the sampling inner tube is installed in the first inner tube through hole. A fixed sleeve is provided, one end of which is connected to the side of the fixed flange away from the vacuum outer pipe, and the other end of which is used to extend into the LNG main pipe; a receiving cavity is provided inside the fixed sleeve, and the sampling inner pipe is received in the receiving cavity; a second inner pipe through hole is provided on the side wall of the receiving cavity away from the fixed flange, and the sampling inner pipe is installed in the second inner pipe through hole and communicates with the LNG main pipe.

[0008] According to the marine LNG sampling probe provided by the present invention, a fixing protrusion is formed on the side wall of the receiving cavity away from the fixing flange, and a second inner tube through hole is provided in the fixing protrusion.

[0009] The marine LNG sampling probe provided by the present invention further includes: An elastic element is provided, and the sampling inner tube is connected to the fixed protrusion through the elastic element.

[0010] According to the marine LNG sampling probe provided by the present invention, the elastic element is wrapped around the outer side of the sampling inner tube, and the side of the elastic element facing the fixed protrusion is connected to the fixed protrusion.

[0011] According to the marine LNG sampling probe provided by the present invention, the end of the fixed sleeve away from the fixed flange is provided with a liquid inlet channel along the radial direction of the sampling inner tube, and the liquid inlet channel is connected to the second inner tube through hole.

[0012] According to the marine LNG sampling probe provided by the present invention, the fixed sleeve includes: The sleeve body has one end connected to the fixed flange on the side away from the vacuum outer tube, and the other end is used to extend into the LNG main pipe. The sleeve body has a receiving cavity inside. An inner tube fixing head is installed at the end of the sleeve body away from the fixing flange. The inner tube fixing head has a second inner tube through hole. Along the radial direction of the sampling inner tube, the inner tube fixing head also has a liquid inlet channel, which communicates with the second inner tube through hole.

[0013] According to the marine LNG sampling probe provided by the present invention, one end of the casing body is connected to the fixed flange by a first elastic connector, and / or, the inner tube fixing head is connected to the end of the casing body away from the fixed flange by a second elastic connector.

[0014] A second aspect of the present invention provides a marine LNG sampling system, comprising: An LNG main pipe is provided with a vacuum sleeve, and a pipe flange is provided on the side of the vacuum sleeve away from the LNG main pipe. The marine LNG sampling probe described in any of the above embodiments, wherein the other end of the vacuum outer tube of the marine LNG sampling probe is connected to the pipeline flange.

[0015] A third aspect of the present invention provides a type testing and certification method for a marine LNG sampling system, used in the aforementioned marine LNG sampling system, comprising: Type testing was conducted on the electrical components of the marine LNG sampling system. Performance and functional tests of the electrical components: Under rated operating conditions, confirm that the switch input function, temperature control function and display accuracy function of the control cabinet of the marine LNG sampling system meet the design requirements; confirm that the electric heating circuit of the marine LNG sampling probe of the marine LNG sampling system is normal in switching on and off; and confirm that the basic display and communication functions of the chromatographic device of the sampling cabinet of the marine LNG sampling system meet the design requirements. Environmental and safety tests on the electrical components: Under preset environmental conditions, the marine LNG sampling system will be subjected to the following tests in sequence: insulation resistance measurement, energy failure test, withstand voltage test, energy fluctuation test, vibration test, high temperature test, low temperature test, alternating damp heat test, salt spray test, and enclosure protection test; the control cabinet will also be subjected to a flame retardancy test. Electromagnetic compatibility testing of electrical components: Conducted emission, radiated emission, electrostatic discharge, radio frequency electromagnetic field radiation, electrical fast transient burst, surge, low-frequency conduction, and radio frequency field induced conducted disturbance immunity tests are performed on the control cabinet and the chromatography device; during and after the tests, the system functions are accepted according to predetermined performance criteria. Type testing was conducted on the mechanical components of the marine LNG sampling system. The overall sealing performance of the marine LNG sampling probe and the BOG sampling probe of the marine LNG sampling system was tested at 1.5 times the design pressure. The sealing performance of the internal pipeline of the sampling cabinet was tested at no less than 1.5 times the rated working pressure. After the pressure was held for a preset time, the pressure drop was determined to be no more than 2% of the test pressure.

[0016] The marine LNG sampling probe provided by this invention can effectively absorb the vertical and horizontal impacts and vibrations generated during equipment operation by adding an elastic connecting pipe (such as a bellows) between the vacuum outer tube and the vaporizer, thereby improving the overall vibration resistance of the probe. This solves the problem that traditional marine LNG sampling probes are prone to fatigue damage under continuous vibration due to excessive structural rigidity and insufficient vibration resistance design, thus ensuring the safety and long-term reliability of the entire sampling system.

[0017] The marine LNG sampling system provided by this invention has at least the advantages mentioned above.

[0018] The type testing and certification method for the marine LNG sampling system provided by this invention offers a clear certification path, avoids repeated trial and error, and improves certification efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is one of the structural schematic diagrams of the marine LNG sampling probe provided by the present invention.

[0021] Figure 2 This is the second schematic diagram of the structure of the marine LNG sampling probe provided by the present invention.

[0022] Figure 3 This is one of the structural schematic diagrams of the fixed base of the marine LNG sampling probe provided by the present invention.

[0023] Figure 4 This is the second schematic diagram of the structure of the fixed base of the marine LNG sampling probe provided by the present invention.

[0024] Figure 5 yes Figure 1 A magnified structural diagram of A in the middle.

[0025] Figure 6 yes Figure 4 A magnified structural diagram at point B in the middle.

[0026] Figure 7 This is a schematic diagram of the structure of the marine LNG sampling system provided by the present invention.

[0027] Figure label: 100. Sampling inner tube; 200. Vaporizer; 300. Flexible connecting tube; 400. Vacuum outer tube; 500. Fixed base; 510. Fixed flange; 520. Fixed sleeve; 511. Flange step surface; 521. Sleeve body; 522. Inner tube fixing head; 523. Receiving cavity; 524. Second inner tube through hole; 525. Fixing protrusion; 526. Liquid inlet channel; 5211. First sleeve step surface; 5212. Second sleeve step surface; 5221. Fixed step surface; 600, Elastic component; 710, First elastic connector; 720, Second elastic connector; 20. LNG main pipe; 30. Vacuum sleeve; 31. Pipe flange; 40. Simulation support. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this 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 this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0029] In the description of this specification, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are used only for the convenience of describing this specification. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this specification. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this specification, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this invention based on the specific circumstances.

[0031] In this specification, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this specification. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0033] In the embodiments of this specification, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0034] The following is combined Figures 1 to 6 The marine LNG sampling probe provided in the embodiments of the present invention will be described.

[0035] like Figures 1 to 3 As shown, a specific embodiment of the first aspect of the present invention provides a marine LNG sampling probe. The marine LNG sampling probe includes a sampling inner tube 100, a vaporizer 200, a flexible connecting tube 300, and a vacuum outer tube 400.

[0036] The inlet end of the sampling inner tube 100 is used to extend into the LNG main pipe 20 for extracting LNG samples. The vaporizer 200 is connected to the outlet end of the sampling inner tube 100 for vaporizing the LNG sample delivered from the sampling inner tube 100. Both the flexible connecting tube 300 and the vacuum outer tube 400 are sleeved on the outside of the sampling inner tube 100; one end of the flexible connecting tube 300 is connected to the vaporizer 200, and one end of the vacuum outer tube 400 is connected to the other end of the flexible connecting tube 300. The other end of the vacuum outer tube 400 is used for installation into the LNG main pipe 20.

[0037] In other words, in this embodiment, an elastic connecting pipe 300 is added between the vacuum outer tube 400 and the vaporizer 200. By adding this elastic connecting pipe 300 (e.g., a bellows) between the vacuum outer tube 400 and the vaporizer 200, the vertical impact and vibration generated during equipment operation can be effectively absorbed, thereby improving the overall vibration resistance of the probe. This solves the problem that traditional marine LNG sampling probes are prone to fatigue damage under continuous vibration environments due to excessive structural rigidity and insufficient vibration resistance design, thus ensuring the safety and long-term reliability of the entire sampling system.

[0038] It should be noted that the elastic connecting tube 300 can undergo elastic deformation in the axial direction of the sampling inner tube 100. This allows it to absorb and buffer axial displacement and stress caused by hull vibration or thermal expansion and contraction, thus protecting precision components such as the sampling inner tube 100 and the vaporizer 200 from impact and fatigue damage, and improving the structural stability and service life of the equipment.

[0039] Preferably, the flexible connecting pipe 300 is a corrugated pipe. The corrugated pipe not only achieves vibration reduction but also ensures the sealing and durability of the structure.

[0040] like Figure 3 As shown, in some embodiments of the present invention, the marine LNG sampling probe further includes a fixed base 500. The fixed base 500 includes a fixed flange 510 and a fixed sleeve 520.

[0041] The other end of the vacuum outer tube 400 is connected to the pipe flange 31 of the LNG main pipe 20 via a fixing flange 510. A first inner tube insertion hole is provided on the fixing flange 510 along the axial direction of the sampling inner tube 100, and the sampling inner tube 100 is installed in the first inner tube insertion hole. Thus, the fixing flange 510 provides the first support point for the sampling inner tube 100. One end of the fixing sleeve 520 is connected to the side of the fixing flange 510 away from the vacuum outer tube 400, and the other end of the fixing sleeve 520 is used to extend into the LNG main pipe 20. By extending the fixing sleeve 520 into the interior of the LNG main pipe 20, a second support point is provided for the slender sampling inner tube 100. The fixed sleeve 520 has a receiving cavity 523 inside, and the sampling inner tube 100 is received in the receiving cavity 523. A second inner tube through hole 524 is provided on the side wall of the receiving cavity 523 away from the fixed flange 510. The sampling inner tube 100 is installed in the second inner tube through hole 524 and is connected to the LNG main pipe 20.

[0042] In other words, the fixed sleeve 520 is inserted into the vacuum sleeve 30 of the LNG main pipe 20. One end of the fixed sleeve 520 is connected to the pipe flange 31 on the vacuum sleeve 30 via the fixed flange 510, and the other end of the fixed sleeve 520 extends into the LNG main pipe 20. Under the combined action of the fixed flange 510 (equivalent to the first support point of the sampling inner pipe 100) and the end of the fixed sleeve 520 away from the fixed flange 510 (equivalent to the second support point of the sampling inner pipe 100), the sampling inner pipe 100 forms a stable double-support structure. This structure enhances the structural stability and bending resistance of the sampling inner pipe 100, suppressing its swaying or displacement within the LNG main pipe 20 caused by fluid impact and external vibration, thereby reducing the risk of fatigue damage and improving the long-term reliability of the equipment.

[0043] The other end of the vacuum outer tube 400 is connected to the side of the fixed flange 510 away from the fixed sleeve 520. The fixed sleeve 520 is used to assemble the vacuum outer tube 400, the pipe flange 31 and the fixed sleeve 520 together. The sampling inner tube 100 passes through the first inner tube through hole, the receiving cavity 523 and the second inner tube through hole 524 in sequence, and then connects to the LNG main pipe 20 for extracting LNG samples from the LNG main pipe 20.

[0044] Optionally, the fixed flange 510 is also provided with an air extraction port, which communicates with the receiving cavity 523 to extract air from the receiving cavity 523, so that the receiving cavity 523 is in a vacuum state. It should be noted that the vacuum degree of the receiving cavity 523 is not less than the preset vacuum degree.

[0045] In some embodiments of the present invention, a fixing protrusion 525 is formed on the side wall of the receiving cavity 523 away from the fixing flange 510, and a second inner tube insertion hole 524 is formed in the fixing protrusion 525. In other words, the local thickening at the location where the second insertion hole is formed in the fixing sleeve 520 can increase the axial length of the second inner tube insertion hole 524, thereby providing a longer and more stable support interface for the sampling inner tube 100 inserted therein. This not only ensures the centering and straightness of the sampling inner tube 100 more accurately, but also suppresses its radial sway in a vibration environment. At the same time, it strengthens the structural rigidity of the support point at the end of the fixing sleeve 520, further improving the stability and fatigue resistance of the entire probe structure.

[0046] In some embodiments of the present invention, the marine LNG sampling probe further includes an elastic element 600. The sampling inner tube 100 is connected to the fixed protrusion 525 via the elastic element 600. This is equivalent to adding the elastic element 600 to the above embodiments. By adding the elastic element 600 at the fixed protrusion 525 of the sampling inner tube 100, the elastic element 600 can absorb and dissipate high-frequency vibrations and minor impacts transmitted from the LNG main pipe 20, providing a buffer protection layer for the sampling inner tube 100, thereby avoiding rigid collisions and stress concentration between the sampling inner tube 100 and the fixed protrusion 525. The elastic element 600 also works in conjunction with the external elastic connecting pipe 300 to form a multi-stage vibration reduction system, further improving the structural stability and service life of the sampling probe in complex vibration environments.

[0047] Optionally, the elastic element 600 wraps around the outer surface of the sampling inner tube 100, with the side of the elastic element 600 facing the fixed protrusion 525 connected to it. This wrapping installation method allows the elastic element 600 to provide circumferential radial buffering for the sampling inner tube 100, absorbing minor vibrations from any direction and preventing direct contact between the sampling inner tube 100 and the rigid fixed protrusion 525, thus avoiding localized stress concentration. Simultaneously, the connection between the elastic element 600 and the fixed protrusion 525 firmly positions the elastic element 600, ensuring that the vibration damping function can stably and continuously act on the preset support point, preventing axial movement or loosening due to vibration or fluid impact, thereby guaranteeing a long-term reliable buffering effect.

[0048] For example, there are multiple elastic elements 600, which are arranged at circumferential intervals along the inner sampling tube 100. This distributed support layout not only facilitates installation and maintenance, but also allows for optimization of vibration reduction by adjusting the number and distribution of the elastic elements 600, resulting in greater design flexibility. Each elastic element 600 abuts against the inner sampling tube 100 on the side facing the central axis, and is connected to the fixed protrusion 525 on the side facing the fixed protrusion 525. This creates multiple independent flexible support points between the inner sampling tube 100 and the fixed protrusion 525, enabling them to work synergistically from multiple directions to absorb and disperse radial vibrations.

[0049] For example, a third inner tube insertion hole is provided on the elastic element 600 along the axial direction of the sampling inner tube 100. The outer surface of the sampling inner tube 100 abuts against the third inner tube insertion hole. The elastic element 600 is equivalent to an elastic bushing. This bushing structure can provide continuous and uniform 360-degree circumferential buffering for the sampling inner tube 100, thereby achieving a stable and consistent vibration reduction effect in all radial directions and maintaining the centered position of the sampling inner tube 100 to prevent eccentric vibration. The side of the elastic element 600 facing the fixed protrusion 525 is also connected to the fixed protrusion 525, which can ensure that the elastic bushing is firmly fixed in the support position (i.e., the fixed protrusion 525), so that it can reliably perform its damping and positioning functions.

[0050] In some embodiments of the present invention, a liquid inlet channel 526 is provided radially along the sampling inner tube 100 at the end of the fixed sleeve 520 away from the fixed flange 510, and the liquid inlet channel 526 communicates with the second inner tube through hole 524. The radial liquid inlet channel 526 can guide the LNG sample smoothly into the sampling inner tube 100, avoiding the direct impact of the main LNG fluid on the inlet of the sampling inner tube 100, thereby reducing fluid-induced vibration and further enhancing the stability of the sampling end.

[0051] For example, the fixed sleeve 520 is integrally cast and has an internal receiving cavity 523. One end of the fixed sleeve 520 is connected to the fixed flange 510, and the other end forms a liquid inlet channel 526 and a second inner tube insertion hole 524. This integrally cast structure eliminates stress concentration points and potential leakage risks that may exist in traditional welded or spliced ​​components, giving the fixed sleeve 520 higher structural strength and overall rigidity, making it more robust and durable under low temperature and high vibration conditions, and improving the safety and reliability of the equipment. A fixing protrusion 525 is formed on the side wall of the receiving cavity 523 away from the fixed flange 510, and the second inner tube insertion hole 524 is opened in the fixing protrusion 525. The setting of the fixing protrusion 525 can further strengthen the support of the sampling inner tube 100, ensuring that the sampling inner tube 100 can also be stably and reliably fixed within the robust sleeve structure, thus forming a stable probe front end structure.

[0052] Optionally, the fixing sleeve 520 is made of alloy.

[0053] In other embodiments of the present invention, the fixing sleeve 520 includes a sleeve body 521 and an inner tube fixing head 522. Designing the fixing sleeve 520 as a split structure makes manufacturing, installation, and maintenance more convenient.

[0054] One end of the sleeve body 521 is connected to the side of the fixed flange 510 away from the vacuum outer pipe 400, and the other end is used to extend into the LNG main pipe 20. The sleeve body 521 has a receiving cavity 523 inside. The inner tube fixing head 522 is installed at the end of the sleeve body 521 away from the fixed flange 510. The inner tube fixing head 522 has a second inner tube through hole 524. Along the radial direction of the sampling inner pipe 100, the inner tube fixing head 522 also has a liquid inlet channel 526, which communicates with the second inner tube through hole 524. By integrating the relatively complex second inner tube through hole 524 and liquid inlet channel 526 into the smaller inner tube fixing head 522, the processing difficulty and cost can be reduced. Compared to machining these structures directly inside the long and deep casing body 521, machining the inner tube fixing head 522 separately can achieve higher machining accuracy and better surface quality, thereby ensuring the precise positioning of the sampling inner tube 100 and the smooth entry of LNG samples.

[0055] In other words, the fixed sleeve 520 is designed as a separate sleeve body 521 and an inner tube fixing head 522. A receiving cavity 523 is formed inside the sleeve body 521. One end of the sleeve body 521 is connected to the fixed flange 510, and the other end is connected to the inner tube fixing head 522. A fixing protrusion 525 is formed on the side of the inner tube fixing head 522 facing the fixed flange 510. The fixing protrusion 525 is received within the receiving cavity 523. A second through hole is provided in the fixing protrusion 525. A liquid inlet channel 526 communicating with the second through hole is also provided on the inner tube fixing head 522.

[0056] like Figure 4 As shown, optionally, one end of the sleeve body 521 is connected to the fixed flange 510 via a first elastic connector 710. This is equivalent to introducing a flexible link at the connection point between the fixed base 500 and the LNG main pipe 20 (i.e., the fixed flange 510), which means setting up a vibration isolation layer in the vibration transmission path. The mechanical vibration transmitted from the LNG main pipe 20 and the pipe flange 31 is effectively absorbed and buffered by this first elastic connector 710 after reaching the fixed flange 510, thereby preventing most of the vibration energy from being directly and rigidly transmitted to the sleeve body 521 that extends into the pipe. By using the first elastic connector 710 to connect one end of the sleeve body 521 to the fixed flange 510, the vibration resistance of the fixed base 500 can be further improved; it not only protects the sleeve body 521 itself and its connection with the inner pipe fixing head 522 from fatigue damage caused by severe vibration, but also provides a more stable macroscopic environment for the internal sampling inner pipe 100, thereby further improving the vibration resistance of the entire fixed base 500 and the long-term operational reliability of the system.

[0057] like Figure 4As shown, optionally, the inner tube fixing head 522 is connected to the end of the sleeve body 521 away from the fixing flange 510 via a second elastic connector 720. That is, a flexible buffer is added at the free end of the fixed sleeve 520, i.e., the position where the vibration displacement may be greatest. This second elastic connector 720 can absorb and dissipate residual vibrations propagating along the sleeve body 521, as well as local vibrations induced by the direct impact of LNG fluid on the sleeve end.

[0058] In conjunction with the first elastic connector 710 at the fixed flange 510, the two components together construct a double-end vibration-damping structure for the fixed sleeve 520, forming a multi-stage vibration isolation system. The first elastic connector 710 primarily isolates vibrations transmitted from the external LNG main pipe 20, while the second elastic connector 720 further processes and dissipates vibrations from the fixed sleeve 520 itself. This graded, multi-point vibration reduction method can maximize the protection of the inner tube fixing head 522 that directly supports the sampling inner tube 100, ensuring the stability of the sampling endpoint, thereby further improving the overall vibration resistance and structural reliability of the fixed base 500.

[0059] Optionally, one end of the sleeve body 521 is connected to the fixed flange 510 via a first elastic connector 710, and the inner tube fixing head 522 is connected to the end of the sleeve body 521 away from the fixed flange 510 via a second elastic connector 720. The first elastic connector 710 and the second elastic connector 720 form a graded, multi-point vibration reduction strategy, which can maximize the protection of the inner tube fixing head 522 that directly supports the sampling inner tube 100, ensure the stability of the sampling endpoint, and further improve the overall vibration resistance and structural reliability of the fixed base 500.

[0060] like Figure 4 As shown, for example, the outer side of the sleeve body 521 facing the fixed flange 510 has a first sleeve step surface 5211, the outer side of the fixed flange 510 facing the sleeve body 521 has a flange step surface 511, the first elastic connector 710 is a rubber sleeve, the rubber sleeve is sleeved on the first sleeve step surface 5211 and the flange step surface 511, and is squeezed by the fixed flange 510 and the sleeve body 521.

[0061] like Figure 4 and Figure 6 As shown, by way of example, a fixed step surface 5221 is formed on the outer side of the inner tube fixing head 522 facing the sleeve body 521, and a second sleeve step surface 5212 is formed on the outer side of the sleeve body 521 facing the inner tube fixing head 522. The second elasticity is a rubber sleeve, which is fitted on the second sleeve step surface 5212 and the fixed step surface 5221, and is squeezed by the sleeve body 521 and the inner tube fixing head 522.

[0062] like Figure 7 As shown, a specific embodiment of the second aspect of the present invention provides a marine LNG sampling system. The marine LNG sampling system includes an LNG header 20 and a marine LNG sampling probe as described in any of the above embodiments. A vacuum sleeve 30 is provided on the LNG header 20, and a pipe flange 31 is provided on the side of the vacuum sleeve 30 away from the LNG header 20; the other end of the vacuum outer tube 400 of the marine LNG sampling probe is connected to the pipe flange 31.

[0063] Since the marine LNG sampling system of this embodiment includes the marine LNG sampling probe of any of the above embodiments, it has at least the above advantages, which will not be repeated here.

[0064] Optionally, the marine LNG sampling system also includes a simulation bracket 40. The simulation bracket 40 is used for mounting to the vibration table and is connected to the marine LNG sampling probe. Using the simulation bracket 40 can improve the installation stability of the marine LNG sampling probe.

[0065] It should be noted that when conducting type testing and certification of the marine LNG sampling system, the marine LNG sampling probe can be connected to the simulation support 40 installed on the vibration table.

[0066] A third aspect of this invention provides a type testing and certification method for a marine LNG sampling system, applicable to any of the above-described embodiments of the marine LNG sampling system. This type testing and certification method for the marine LNG sampling system includes two aspects: one is conducting type testing on the electrical components of the marine LNG sampling system; the other is conducting type testing on the mechanical components of the marine LNG sampling system.

[0067] The steps for type testing of the electrical components of a marine LNG sampling system include: Performance and functional tests of the electrical components: Under rated operating conditions, confirm that the switch input function, temperature control function and display accuracy function of the control cabinet of the marine LNG sampling system meet the design requirements; confirm that the electric heating circuit of the marine LNG sampling probe of the marine LNG sampling system is normal in switching on and off; and confirm that the basic display and communication functions of the chromatographic device of the sampling cabinet of the marine LNG sampling system meet the design requirements. Environmental and safety tests on the electrical components: Under preset environmental conditions, the marine LNG sampling system will be subjected to the following tests in sequence: insulation resistance measurement, energy failure test, withstand voltage test, energy fluctuation test, vibration test, high temperature test, low temperature test, alternating damp heat test, salt spray test, and enclosure protection test; the control cabinet will also be subjected to a flame retardancy test. Electromagnetic compatibility testing of electrical components: Conducted emission, radiated emission, electrostatic discharge, radio frequency electromagnetic field radiation, electrical fast transient burst, surge, low frequency conduction, and radio frequency field induction conducted disturbance immunity tests are performed on the control cabinet and the chromatography device; during and after the tests, the system functions are accepted according to predetermined performance criteria.

[0068] The steps for type testing of the mechanical components of a marine LNG sampling system include: The overall sealing performance of the marine LNG sampling probe and the BOG sampling probe of the marine LNG sampling system was tested at 1.5 times the design pressure. The sealing performance of the internal pipeline of the sampling cabinet was tested at no less than 1.5 times the rated working pressure. After the pressure holding time was preset (e.g., 15 minutes), it was determined that the pressure drop did not exceed 2% of the test pressure, indicating that the sealing performance was qualified.

[0069] The type testing and certification method for the marine LNG sampling system provided in this embodiment offers a clear certification path, avoiding repeated trial and error and improving certification efficiency.

[0070] In some embodiments of the present invention, before type testing and certification of the marine LNG sampling system, the method further includes: inspecting the appearance of the marine LNG sampling system; and if the appearance inspection is qualified, conducting type testing on the electrical components of the marine LNG sampling system and / or conducting type testing on the mechanical components of the marine LNG sampling system.

[0071] For example, this embodiment provides a marine LNG sampling system. The system includes a control cabinet (model PS7300-MA), a sampling cabinet (model PS7300-MB), and a sampling probe from any of the above embodiments. The type testing and certification method for the system includes the following steps: Visual inspection: A visual inspection of the marine LNG sampling system was conducted according to design requirements.

[0072] Electrical component testing: The test conditions are as follows: (1) The equipment under test shall operate at its rated operating voltage and frequency (AC equipment). The equipment under test includes control cabinets, marine LNG sampling probes, etc.

[0073] (2) The test site should be maintained within the following standard atmospheric conditions: temperature range: 15℃~35℃; relative humidity: 30%~90%; air pressure: 86kPa~106kPa.

[0074] The functions of the control cabinet are verified according to the design requirements, including tests on the switch input function and the temperature controller function.

[0075] Perform an overall test on the analog input of the system to verify whether the displayed values ​​and the output values ​​of the field instruments are within the allowable error range.

[0076] Determine whether the test component is functioning properly based on the functional test design requirements of the sampling probe electric heater.

[0077] Determine whether the test components are functioning properly based on the functional test design requirements of the sampling cabinet chromatography device.

[0078] The insulation resistance of the verification equipment is within the specified range, and is measured twice: before and after the alternating damp heat test, low temperature test, salt spray test, and withstand voltage test. Existing insulation resistance measurement methods can be used. The test voltage is set to DC 500V. The required insulation resistance values ​​are: not less than 100 MΩ before the test, and not less than 10 MΩ after the test.

[0079] When disconnecting and reconnecting power, check the equipment's functionality to ensure it is in good working order.

[0080] Verify the insulation characteristics between the individual circuits of the equipment and between all circuits and the chassis. The test conditions are: test voltage 1500V; test frequency 50Hz.

[0081] The verification equipment itself generates emission interference that meets standard requirements, and also has the ability to resist external electromagnetic interference.

[0082] Energy fluctuation test: Verify that the equipment functions normally when the power supply fluctuates. The operating procedure follows Section 2.4 of the "Guidelines for Type Approval Testing of Electrical and Electronic Products"—Power Fluctuation Test. The test conditions are selected as AC power fluctuations. The test method is applicable to all equipment, computers, and other electronic devices used for control, protection, safety, monitoring, alarm, and internal communication. The test results are applicable to electrical and electronic equipment other than motors and transformers.

[0083] Vibration test: Verify that the equipment functions normally under the influence of ship vibration. The operating procedure follows Section 2.7 – Vibration Test – of the "Guidelines for Type Approval Testing of Electrical and Electronic Products". Specifically, the vibration test parameters are selected based on general vibration conditions and the installation location.

[0084] High temperature test: Verify that the equipment can operate normally under high temperatures. The operating method follows Section 2.8 – High Temperature Test – of the “Guideline for Type Approval Testing of Electrical and Electronic Products”. Specifically, the selected temperature for the PS7300-MA control cabinet is 55℃±2℃; and the selected temperature for the PS7300-MB sampling cabinet (chromatographic apparatus) and marine LNG sampling probe (electric heater) is 70℃±2℃.

[0085] Low temperature test: The verification confirmed that the equipment could operate normally under low temperatures, and the operating method followed Section 2.9 – Low Temperature Test – of the "Guideline for Type Approval Testing of Electrical and Electronic Products". Based on customer requirements, the low temperature test for the PS7300-MA control cabinet was conducted at an ambient temperature of -18℃. Specifically, the selected temperature for the PS7300-MA control cabinet was -18℃ ± 3℃; the selected temperature for the PS7300-MB sampling cabinet (chromatographic apparatus) and the PS7300-MC LNG sampling probe (electric heater) was -25℃ ± 3℃.

[0086] Alternating damp heat test: The verification confirmed that the equipment could operate normally under humid heat conditions. The operating method followed Section 2.10 of the "Guidelines for Type Approval Testing of Electrical and Electronic Products"—Alternating Humid Heat Test. The test conditions were set for a duration of 2 cycles (24 hours per cycle).

[0087] Salt spray test Kb: To verify that the equipment does not suffer corrosion damage or affect normal operation under the influence of salt spray environment, the operating method refers to Section 2.12 of the "Guideline for Type Approval Testing of Electrical and Electronic Products" - Salt Spray Test Kb.

[0088] Enclosure protection test: To verify whether the enclosure protection of the equipment meets the requirements of the corresponding protection level, the operating method refers to Section 2.15 of the "Guidelines for Type Approval Testing of Electrical and Electronic Products" - Enclosure Protection Test.

[0089] Mechanical component testing: Pressure test: After drilling through the sampling port at the front end of the LNG sampling probe, the entire LNG sampling probe is fully connected. A 1.5 MPa pressure test (1.5 times the design pressure) is then performed on the outside of the sampling probe rod and the entire sampling inner tube inside the sampling probe using a test fixture.

[0090] Connect the entire BOG sampling probe and use a test fixture to perform a 1.5 MPa pressure test (1.5 times the design pressure) on the outside of the sampling probe rod and the entire sampling tube inside the sampling probe.

[0091] The internal piping of the sampling cabinet is fully connected and pressure tested at a pressure greater than 1.5 times the rated working pressure. Specifically, sample flow path 1 (including the chromatograph carrier gas flow path), sample flow path 2, and chromatograph standard gas flow path are pressure tested at 0.7 MPa, and the vacuum flow path is pressure tested at 0.15 MPa.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A marine LNG sampling probe, characterized in that, include: The sampling inner tube (100) has its inlet end inserted into the LNG main pipe (20) for extracting LNG samples. A vaporizer (200) is connected to the outlet end of the sampling inner tube (100); An elastic connecting tube (300) is sleeved on the outside of the sampling inner tube (100); one end of the elastic connecting tube (300) is connected to the vaporizer (200); A vacuum outer tube (400) is sleeved on the outside of the sampling inner tube (100); one end of the vacuum outer tube (400) is connected to the other end of the elastic connecting tube (300), and the other end of the vacuum outer tube (400) is used to install to the LNG main pipe (20).

2. The marine LNG sampling probe according to claim 1, characterized in that, It also includes a fixed base (500); the fixed base (500) includes: A fixed flange (510) is provided, and the other end of the vacuum outer tube (400) is connected to the pipeline flange (31) of the LNG main pipe (20) through the fixed flange (510); along the axial direction of the sampling inner tube (100), a first inner tube through hole is provided on the fixed flange (510), and the sampling inner tube (100) is installed in the first inner tube through hole. A fixed sleeve (520) is provided, one end of which is connected to the side of the fixed flange (510) away from the vacuum outer tube (400), and the other end of which is used to extend into the LNG main pipe (20). A receiving cavity (523) is provided inside the fixed sleeve (520), and the sampling inner tube (100) is contained in the receiving cavity (523). A second inner tube through hole (524) is provided on the side wall of the receiving cavity (523) away from the fixed flange (510). The sampling inner tube (100) is installed in the second inner tube through hole (524) and communicates with the LNG main pipe (20).

3. The marine LNG sampling probe according to claim 2, characterized in that, A fixing protrusion (525) is formed on the side wall of the receiving cavity (523) away from the fixing flange (510), and the fixing protrusion (525) is provided with a second inner tube through hole (524).

4. The marine LNG sampling probe according to claim 3, characterized in that, Also includes: The sampling inner tube (100) is connected to the fixed protrusion (525) via the elastic element (600).

5. The marine LNG sampling probe according to claim 4, characterized in that, The elastic element (600) is wrapped around the outer side of the sampling inner tube (100), and the side of the elastic element (600) facing the fixing protrusion (525) is connected to the fixing protrusion (525).

6. The marine LNG sampling probe according to any one of claims 2 to 5, characterized in that, The fixed sleeve (520) has a liquid inlet channel (526) at one end away from the fixed flange (510) along the radial direction of the sampling inner tube (100), and the liquid inlet channel (526) is connected to the second inner tube through hole (524).

7. The marine LNG sampling probe according to any one of claims 2 to 5, characterized in that, The fixed sleeve (520) includes: The sleeve body (521) has one end connected to the fixed flange (510) on the side away from the vacuum outer tube (400), and the other end is used to extend into the LNG main pipe (20). The sleeve body (521) has a receiving cavity (523) inside. An inner tube fixing head (522) is installed at one end of the sleeve body (521) away from the fixing flange (510). The inner tube fixing head (522) has a second inner tube through hole (524). Along the radial direction of the sampling inner tube (100), the inner tube fixing head (522) also has a liquid inlet channel (526), ​​which is connected to the second inner tube through hole (524).

8. The marine LNG sampling probe according to claim 7, characterized in that, One end of the sleeve body (521) is connected to the fixed flange (510) via a first elastic connector (710), and / or, the inner tube fixing head (522) is connected to the end of the sleeve body (521) away from the fixed flange (510) via a second elastic connector (720).

9. A marine LNG sampling system, characterized in that, include: An LNG main pipe (20) is provided with a vacuum sleeve (30), and a pipe flange (31) is provided on the side of the vacuum sleeve (30) away from the LNG main pipe (20). The marine LNG sampling probe according to any one of claims 1 to 8, wherein the other end of the vacuum outer tube (400) of the marine LNG sampling probe is connected to the pipeline flange (31).

10. A type testing and certification method for a marine LNG sampling system, characterized in that, The marine LNG sampling system of claim 9 includes: Type testing was conducted on the electrical components of the marine LNG sampling system. Performance and functional tests of the electrical components: Under rated operating conditions, confirm that the switch input function, temperature control function and display accuracy function of the control cabinet of the marine LNG sampling system meet the design requirements; confirm that the electric heating circuit of the marine LNG sampling probe of the marine LNG sampling system is normal in switching on and off; and confirm that the basic display and communication functions of the chromatographic device of the sampling cabinet of the marine LNG sampling system meet the design requirements. Environmental and safety tests on the electrical components: Under preset environmental conditions, the marine LNG sampling system will be subjected to the following tests in sequence: insulation resistance measurement, energy failure test, withstand voltage test, energy fluctuation test, vibration test, high temperature test, low temperature test, alternating damp heat test, salt spray test, and enclosure protection test; the control cabinet will also be subjected to a flame retardancy test. Electromagnetic compatibility testing of electrical components: Conducted emission, radiated emission, electrostatic discharge, radio frequency electromagnetic field radiation, electrical fast transient burst, surge, low-frequency conduction, and radio frequency field induced conducted disturbance immunity tests are performed on the control cabinet and the chromatography device; during and after the tests, the system functions are accepted according to predetermined performance criteria. Type testing was conducted on the mechanical components of the marine LNG sampling system. The overall sealing performance of the marine LNG sampling probe and the BOG sampling probe of the marine LNG sampling system was tested at 1.5 times the design pressure. The sealing performance of the internal pipeline of the sampling cabinet was tested at no less than 1.5 times the rated working pressure. After the pressure was held for a preset time, the pressure drop was determined to be no more than 2% of the test pressure.

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