Portable LNG sampler

Abstract

The utility model discloses a portable LNG sampler, including gas gathering pipeline, needle valve, bypass branch, bypass valve, pressure gauge and gas collection bag, before gas gathering, utilize bypass branch and bypass valve cooperation, to the air replacement of gas gathering pipeline, when gas gathering, adopt double needle valve control gas collection bag and take the air, and through pressure gauge real -time monitoring gas gathering pressure, like this ensure sampling safety. The sampler adopts gas phase sampling to replace the traditional liquid sampling, is applicable to any LNG gas station, and the application field is wide, effectively avoids the safety problem that liquid sampling leads to personnel frostbite, has higher popularization value.

Description

Technical Field

[0001] This utility model belongs to the field of natural gas detection technology, and relates to natural gas sampling, specifically to a portable LNG sampler. Background Technology

[0002] With the rapid increase in the number of liquefied natural gas (LNG) refueling stations and the continuous rise in sales volume, the demand for LNG quality testing (quality indicators such as component purity and calorific value) is becoming increasingly stringent. However, the cryogenic characteristics of LNG present significant technical bottlenecks for its liquid sampling, as follows: 1. Safety risks: LNG has a boiling point of -160℃ at normal pressure. Direct liquid sampling can easily cause frostbite to personnel. Moreover, it is not easy to maintain the liquid sample for a long time. As the LNG vaporizes over time, the pressure inside the gasbag storing the sample increases due to the continuous vaporization of LNG, which may cause it to overpressure and burst, posing a risk of explosion, injury, and leakage. 2. Cost issues: Liquid sampling relies on on-site chromatography for testing, and the cost of a single device is high, making it difficult to popularize in large-scale gas station networks; 3. Time-sensitivity defect: During the transportation of liquid samples, components may evaporate due to temperature changes, affecting the accuracy of detection.

[0003] Existing technologies mostly focus on improving liquid sampling equipment or reducing detection energy consumption through cold energy utilization technology, but none of them have solved the core problem. Utility Model Content

[0004] To address the aforementioned issues, the main objective of this invention is to design a portable LNG sampler that uses a gas-phase sampling method instead of a liquid-phase sampling method to solve the safety, cost, and timeliness problems associated with LNG sampling.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A portable LNG sampler for LNG gas phase sampling includes: The gas collection pipeline has a flange at its first end that connects to the gas phase port of the tank truck, and a quick-connect fitting at its last end for LNG gas phase collection. Needle valve, including a first needle valve and a second needle valve connected in series on the gas extraction pipeline; The bypass branch connects to the gas extraction pipeline at one end, with the connection point located between the first needle valve and the second needle valve, and extends to the safe discharge area at the other end. Bypass valve, installed on bypass branch line; The pressure gauge is installed on the gas sampling pipeline and is located between the first needle valve and the bypass branch connection point; The gas collection bag includes an air inlet, an air outlet, an air inlet valve at the air inlet, an air outlet valve at the air outlet, and a quick-connect fitting for the air inlet to the gas collection pipeline.

[0006] As a further description of this utility model, the gas extraction pipeline is made of austenitic stainless steel.

[0007] As a further description of this utility model, the flange includes a medium discharge hole located in the middle and bolt fixing holes located around the perimeter, the medium discharge hole being connected to the gas sampling pipeline.

[0008] As a further description of this utility model, the gas collection bag is made of high-strength aluminum film, including one of aluminum-plastic composite film, perfluorinated film jacketed aluminum film, and nano-functionalized aluminum film.

[0009] As a further description of this utility model, the water volume of the gas collection bag is 5L, the burst pressure is ≥0.2MPa, and the initial state is set to a negative pressure flat state with the air inlet valve and air outlet valve closed.

[0010] As a further description of this utility model, the pressure gauge is configured as a mechanical pressure gauge.

[0011] Compared with the prior art, the technical effects of this utility model are as follows: This invention provides a portable LNG sampler, comprising a gas sampling pipeline, a needle valve, a bypass branch, a bypass valve, a pressure gauge, and a gas collection bag. Before sampling, the bypass branch and bypass valve work together to purge the air from the gas sampling pipeline. During sampling, a double needle valve controls the gas collection bag's intake, and the pressure gauge monitors the sampling pressure in real time to ensure sampling safety. This sampler uses gas phase sampling instead of traditional liquid sampling, is suitable for any LNG refueling station, has a wide range of applications, effectively avoids the safety issues of frostbite caused by liquid sampling, and has high promotional value.

[0012] Furthermore, this invention employs a high-strength aluminum film gas collection bag, in conjunction with a double-needle valve, to achieve precise pressure control of 0.3-1.2 MPa during LNG gas phase sampling, reducing sampling risks. It features safety, reliability, ease of operation, and suitability for on-site use. The double-needle valve, along with a bypass valve and pressure gauge, prevents LNG leakage caused by excessive pressure or rapid valve opening during sampling, effectively controlling pressure and reducing sampling risks. The gas collection bag is equipped with an inlet and an outlet, both with one-way valves, enabling timely sampling and testing to prevent LNG quality issues. Additionally, the gas collection bag is made of high-strength aluminum film, facilitating storage and transportation. Attached Figure Description

[0013] Figure 1 This is an overall structural view of the present invention.

[0014] In the diagram, 1. Gas sampling pipeline, 2. Needle valve, 21. First needle valve, 22. Second needle valve, 3. Bypass branch, 4. Bypass valve, 5. Pressure gauge, 6. Gas collection bag, 61. Inlet, 62. Outlet, 7. Flange, 8. Quick-connect coupling. Detailed Implementation

[0015] The present invention will now be described in detail with reference to the accompanying drawings: In one embodiment of this utility model, a portable LNG sampler is disclosed, such as... Figure 1 As shown, the sampler is used for LNG gas phase sampling and includes: gas sampling pipeline 1, needle valve 2, bypass branch 3, bypass valve 4, pressure gauge 5, and gas collection bag 6. The bypass branch 3, in conjunction with the bypass valve 4, performs air replacement on the gas sampling pipeline 1 before gas sampling. The double needle valve 2 controls the gas collection bag 6 to extract gas. During the gas sampling process, the pressure gauge 5 monitors the gas sampling pressure in real time to ensure sampling safety.

[0016] Specifically, in this embodiment, the above-mentioned components are described in detail as follows: Gas collection pipeline 1: Its first end is equipped with a flange 7 connecting to the gas phase port of the tank truck, and its last end is equipped with a quick-connect fitting 8 for LNG gas phase collection. The quick-connect fitting 8 is a self-sealing quick-connect fitting made of 316L stainless steel, suitable for the low-temperature environment of the LNG tank truck gas phase port. When disconnected, it automatically closes the channel to prevent natural gas leakage. Alternatively, a snap-fit ​​pneumatic fitting with a press-lock mechanism can be selected as needed, supporting one-handed operation. The quick-connect fitting 8 has a limiting part on the outside that cooperates with the gas collection bag 6. This limiting part includes threads, snaps, etc.

[0017] In this embodiment, the gas sampling pipeline 1 is made of austenitic stainless steel, such as 304L or 316L, whose low-temperature impact toughness meets the requirement of Akv≥40J at -196℃; the flange 7 includes a medium discharge hole located in the middle and bolt fixing holes located around the perimeter. The medium discharge hole is connected to the gas sampling pipeline 1 to ensure the smooth flow of the gas sampling pipeline when taking gas, and the bolt fixing holes are used to fix the flange 7 to the gas phase port of the tank truck.

[0018] Needle valve 2: includes a first needle valve 21 and a second needle valve 22 connected in series on the gas sampling pipeline 1. The first needle valve 21 is located at the front of the gas sampling pipeline 1, and the second needle valve 22 is located at the rear of the gas sampling pipeline 1. During the gas sampling process, the first needle valve 21 and the bypass valve 4 can be opened to replace air as needed, or the first needle valve 21 and the second needle valve 22 can be opened simultaneously while the bypass valve 4 is closed to perform the gas sampling operation.

[0019] Bypass branch 3: One end of it is connected to the gas sampling pipeline 1, with the connection point located between the first needle valve 21 and the second needle valve 22, and the other end extends to the safe discharge area, which includes a gas recovery device.

[0020] Bypass valve 4: It is set as a needle valve and installed on the bypass branch 3. It is used to open or close the bypass branch 3 according to the gas extraction needs.

[0021] In this embodiment, by using bypass branch 3 in conjunction with bypass valve 4, the first needle valve 21 and bypass valve 4 are opened before gas sampling begins. This allows air and impurities in the gas sampling pipeline 1 to be discharged to a safe discharge area via bypass branch 3, ensuring the purity of the subsequently collected natural gas samples. Furthermore, bypass branch 3 is located between the first needle valve 21 and the second needle valve 22, serving as an emergency discharge channel in case the valve bodies (first needle valve 21 and second needle valve 22) fail during gas sampling, thus avoiding the risk of overpressure.

[0022] Pressure gauge 5: Installed on the gas sampling pipeline 1 and located between the connection point of the first needle valve 21 and the bypass branch 3, to avoid interference of the bypass branch 3 on the measurement data. At the same time, it provides real-time feedback on the gas sampling pressure inside the gas sampling pipeline 1 to ensure that the gas sampling pressure is controllable.

[0023] In this embodiment, pressure gauge 5 is set as a mechanical pressure gauge.

[0024] Gas collection bag 6: includes an air inlet 61, an air outlet 62, an air inlet valve at the air inlet 61, and an air outlet valve at the air outlet 62. The air inlet 61 is connected to the quick-connect fitting 8 of the gas collection pipeline 1, and gas enters through pressure difference.

[0025] In this embodiment, the gas collection bag 6 is made of high-strength aluminum membrane, with a water volume of 5L and a burst pressure ≥0.2MPa. The initial state of the gas collection bag 6 is set to a negative pressure flat state with the inlet and outlet valves closed. High-strength aluminum membrane is a functional material widely used in industrial applications, especially possessing unique advantages in pressure resistance, corrosion resistance, and adaptability to extreme environments. The high-strength aluminum membrane can be, but is not limited to, aluminum-plastic composite membranes, perfluorinated membrane jacketed aluminum membranes, and nano-functionalized aluminum membranes. In this embodiment, for LNG gas phase sampling, perfluorinated membrane jacketed aluminum membranes (elongation ≥12% at -196℃) are preferentially selected.

[0026] It should be noted that the exhaust valve is a one-way valve, while the inlet valve controls the gas inflow and connects to the quick-connect connector 8. The exhaust valve is used for other releases or connected to the detection port, ensuring that gas can only enter the gas collection bag 8 in one direction, preventing gas backflow and sample contamination. Additionally, the inlet 61 includes a groove or thread that mates with the limiting part of the quick-connect connector 8, and the outlet 62 includes a fixing structure that mates with the detection port. This fixing structure can be configured according to the specific detection port.

[0027] The portable LNG sampler disclosed above first connects flange 7 to the gas phase of the tank truck and connects the gas inlet of gas collection bag 6 to quick-connect connector 8. Then, the first needle valve 21 and the bypass valve 4 on the bypass branch 3 are opened to replace the air and impurities in the gas collection pipeline 1. The replacement time is 5 seconds. After the gas flow is stable and controllable, the bypass valve 4 is closed. Then, the second needle valve 22 is opened to start the gas collection operation, allowing the gas to enter the gas collection bag 6. After the gas collection is completed, the tank truck and the double needle valve 2 are closed.

[0028] The above content discloses the technical solution of this utility model, which has the following advantages over the prior art: 1. This utility model uses gas phase sampling to replace traditional liquid sampling, which is applicable to any LNG refueling station and has a wide range of applications. It can effectively avoid the safety problem of frostbite caused by liquid sampling and has high promotion value. 2. This utility model uses a high-strength aluminum film gas collection bag, which, in conjunction with a double needle valve, can achieve precise pressure control of 0.3-1.2MPa during LNG gas phase sampling, reducing sampling risks and featuring safety, reliability, simple operation, and ease of on-site use; 3. This utility model uses a double needle valve and a bypass valve in conjunction with a pressure gauge to prevent LNG leakage during sampling due to excessive pressure or too rapid valve opening, effectively controlling the pressure and reducing sampling risks. 4. The gas collection bag of this utility model includes an air inlet and an air outlet, and a one-way valve is provided at both the air inlet and the air outlet to enable timely sampling and testing, preventing LNG quality problems. At the same time, the gas collection bag is made of high-strength aluminum film, which is convenient for storage and transportation.

[0029] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A portable LNG sampler, characterized in that, This sampler is used for LNG gas phase sampling and includes: The gas collection pipeline has a flange at its first end that connects to the gas phase port of the tank truck, and a quick-connect fitting at its last end for LNG gas phase collection. Needle valve, including a first needle valve and a second needle valve connected in series on the gas extraction pipeline; The bypass branch connects to the gas extraction pipeline at one end, with the connection point located between the first needle valve and the second needle valve, and extends to the safe discharge area at the other end. Bypass valve, installed on bypass branch line; The pressure gauge is installed on the gas sampling pipeline and is located between the first needle valve and the bypass branch connection point; The gas collection bag includes an air inlet, an air outlet, an air inlet valve at the air inlet, an air outlet valve at the air outlet, and a quick-connect fitting for the air inlet to the gas collection pipeline.

2. The portable LNG sampler according to claim 1, characterized in that: The gas extraction pipeline is made of austenitic stainless steel.

3. A portable LNG sampler according to claim 1 or 2, characterized in that: The flange includes a medium discharge port located in the middle and bolt fixing holes located around the perimeter. The medium discharge port is connected to the gas sampling pipeline.

4. A portable LNG sampler according to claim 1, characterized in that: The gas collection bag is made of high-strength aluminum film, including one of the following: aluminum-plastic composite film, perfluorinated film jacketed aluminum film, and nano-functionalized aluminum film.

5. A portable LNG sampler according to claim 4, characterized in that: The water volume of the gas collection bag is 5L, the burst pressure is ≥0.2MPa, and the initial state is set to a negative pressure flat state with the inlet valve and outlet valve closed.

6. A portable LNG sampler according to claim 1, characterized in that: The pressure gauge is set to a mechanical pressure gauge.

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