Method for extracting high-purity helium and filling BOG (Boil Off Gas)

Abstract

The invention belongs to the technical field of helium filling, and particularly relates to a filling method for extracting high-purity helium from BOG, the high-purity helium extracted from BOG is conveyed to a high-purity helium buffer tank, then pressurized by a compressor and conveyed to a filling station, the filling station is provided with a first filling port and a second filling port, the high-purity helium is filled into a first long pipe through the first filling port, and the second long pipe is filled into a second long pipe through the second filling port. When a second long pipe needs to be filled with high-purity helium, the second long pipe is connected with a second filling port and communicated with a pressure equalizing pipeline, the high-purity helium pressurized by a compressor and the high-purity helium in the first long pipe are both filled into the second long pipe, and the residual high-purity helium in the first long pipe is conveyed into a high-purity helium buffer tank through a pressure reducing pipeline and then is pressurized by the compressor, so that the high-purity helium is filled into the high-purity helium buffer tank. And the second long pipe is filled with the liquid through the second filling opening. The filling time of the second long pipe is shortened, and the filling efficiency of the second long pipe is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of helium filling, and in particular relates to a method for filling BOG with high-purity helium extracted from the BOG. Background Art

[0002] Helium is a rare gas that is abundant in the universe but rare on Earth. It mainly exists in the atmosphere, rocks and natural gas. Helium is usually a colorless and odorless gas. It is the only substance that cannot solidify under standard atmospheric pressure. Its special physical properties determine the special uses of helium. As a scarce strategic resource for the development of national defense and high-tech industries, helium is widely used in military industry, scientific research, petrochemicals, refrigeration, medical treatment, semiconductors, pipeline leak detection, superconducting experiments, metal manufacturing, deep-sea diving, high-precision welding, optoelectronic product production and other fields, which is of great significance to scientific research.

[0003] Helium has a low content, is difficult to extract, and has a high cost. Currently, it is mainly extracted from natural gas BOG. ​​However, since the helium content in LNG raw gas is very low, its content is only about 260~650PPmm, which will result in low helium production.

[0004] The existing method of filling high-purity helium is generally to directly fill the high-purity helium extracted from BOG into a long tube truck through a membrane press. This method takes too long to fill, generally about 7 to 15 days, resulting in low utilization rate of the customer's long tube. Summary of the invention

[0005] The object of the present invention is to provide a method for filling BOG with high-purity helium, so as to solve the technical problem of low utilization rate of customer's long tubes caused by the existing filling method.

[0006] In order to achieve the above technical purpose, the technical solution of the present invention is: A method for extracting high-purity helium from BOG and filling it, comprising the following steps: S1. The high-purity helium extracted from BOG is transported to a high-purity helium buffer tank. The high-purity helium in the high-purity helium buffer tank is pressurized by a compressor and then transported to a filling station. The filling station is provided with a first filling port and a second filling port. The first filling port and the second filling port are connected through a pressure-equalizing pipeline. The first filling port is connected to a first long tube. The high-purity helium is filled into the first long tube through the first filling port. S2. When the second long tube needs to be filled with high-purity helium, the second long tube is connected to the second filling port and connected to the pressure equalizing pipeline, and the high-purity helium pressurized by the compressor and the high-purity helium in the first long tube are both filled into the second long tube; S3. The first long tube is also connected to a pressure reducing pipeline, and the remaining high-purity helium in the first long tube is transported to the high-purity helium buffer tank through the pressure reducing pipeline, and then pressurized by a compressor and filled into the second long tube through the second filling port.

[0007] As an improvement, in step S2, after the second long tube is connected to the second filling port, the high-purity helium in the high-purity helium buffer tank is used as the gas source to perform positive pressure replacement or vacuum replacement on the gas in the hose in front of the main valve of the second long tube. After the replacement is completed, the gas in the hose in front of the main valve of the second long tube is analyzed, and the second long tube is filled after the analysis is qualified.

[0008] As a further improvement, in step S2, the first long tube and the second long tube are provided with a plurality of tubes, and the high-purity helium in the first long tube is filled into the second long tube by pressure equalization one by one, and the specific method is: One first long tube is sequentially filled into a plurality of second long tubes, and the above steps are repeated to sequentially fill the other first long tubes into the plurality of second long tubes.

[0009] As a further improvement, the filling station is further provided with a third filling port, through which the container compartment or the loose bottles are filled.

[0010] As a further improvement, a pressure-maintaining valve is provided at the outlet of the compressor, and the pressure of the pressure-maintaining valve is 10 MPa.

[0011] As a further improvement, the steps of positive pressure displacement are: The compressor outlet is also connected to a purge and cleaning pipeline. After the high-purity helium in the high-purity helium buffer tank is pressurized by the compressor, the high-purity helium is filled into the hose in front of the second long tube main valve through the purge and cleaning pipeline until the pressure in the hose in front of the second long tube main valve reaches 1.0MPa, and then the gas in the hose in front of the second long tube main valve is recovered into the airbag to complete a positive pressure replacement. The above steps are repeated to perform positive pressure replacement on the hose in front of the second long tube main valve for multiple times until the hose in front of the second long tube main valve meets the filling standard.

[0012] As a further improvement, the steps of vacuum replacement are: The hose in front of the second long tube main valve is evacuated by a vacuum pump until the vacuum degree in the hose in front of the second long tube main valve is <10Pa, and then the high-purity helium in the high-purity helium buffer tank is pressurized by a compressor, and then filled into the hose in front of the second long tube main valve through the purge and clean pipeline until the pressure in the hose in front of the second long tube main valve reaches 0.3MPa. At this time, the gas in the hose in front of the second long tube main valve is recovered into the airbag to complete a vacuum replacement, and the above steps are repeated to perform a second vacuum replacement on the hose in front of the second long tube main valve until the hose in front of the second long tube main valve meets the filling standard.

[0013] As a further improvement, after the gas analysis in the hose in front of the second long tube main valve is qualified, the second long tube main valve is opened, and the gas in the second long tube enters the hose in front of the second long tube main valve. The gas in the second long tube is used as the gas source to perform vacuum replacement or positive pressure replacement on the hose in front of the second long tube main valve. After the replacement is completed, the gas in the hose in front of the second long tube main valve is analyzed again. After the analysis is qualified, the second long tube can be filled.

[0014] As a further improvement, the outlet of the high-purity helium buffer tank is connected to a compressor, and a main filling pipeline is provided at the outlet of the compressor, the main filling pipeline is connected to the first filling pipeline and the second filling pipeline respectively, and the first filling port and the second filling port are respectively arranged at the ends of the first filling pipeline and the second filling pipeline; The inlet of the pressure reducing pipeline is connected to the first long pipe, the outlet of the pressure reducing pipeline is connected to the high-purity helium buffer tank, and a self-operated regulating valve is arranged on the pressure reducing pipeline.

[0015] As a further improvement, the first filling pipeline, the second filling pipeline and the pressure reducing pipeline are all connected with a vacuum pipeline, a recovery pipeline and an analysis pipeline. The end of the vacuum pipeline is connected to a vacuum pump, the end of the recovery pipeline is connected to an air bag, and an analysis sampling port is provided at the end of the analysis pipeline. A purge and cleaning pipeline is connected between the main filling pipeline and the pressure equalizing pipeline, and a self-operated regulating valve is provided on the purge and cleaning pipeline.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are: The method for filling high-purity helium by extracting BOG provided by the present invention, when the second long tube needs to be filled, the high-purity helium in the first long tube is filled into the second long tube by means of equalizing pressure one by one, and then the remaining high-purity helium in the first long tube enters the high-purity helium buffer tank through the pressure reducing pipeline, and then is pressurized by the compressor and filled into the second long tube, and the method shortens the filling time of the second long tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a process flow chart of the present invention; Figure 2 is a flow chart of the device of the present invention; Among them, 1-high-purity helium buffer tank, 2-compressor, 3-main filling pipeline, 4-first filling pipeline, 5-second filling pipeline, 6-first long tube, 7-second long tube, 8-pressure reducing pipeline, 9-pressure equalizing pipeline, 10-pressure maintaining valve, 11-purge and cleaning pipeline, 12-analysis pipeline, 13-recovery pipeline, 14-air bag, 15-third filling pipeline, 16-vacuum pipeline, 17-vacuum pump. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] like Figure 1-2 As shown, a method for extracting high-purity helium from BOG and filling it comprises the following steps: S1. The high-purity helium extracted from BOG is transported to a high-purity helium buffer tank. The high-purity helium in the high-purity helium buffer tank is pressurized by a compressor and then transported to a filling station. The filling station is provided with a first filling port and a second filling port. The first filling port is connected to a first long tube. The high-purity helium is filled into the first long tube through the first filling port. S2. When the second long tube needs to be filled with high-purity helium, the second long tube is connected to the second filling port. First, the high-purity helium in the high-purity helium buffer tank is used as the gas source to perform positive pressure replacement or vacuum replacement on the hose in front of the main valve of the second long tube. After the replacement is completed, the gas in the hose in front of the main valve of the second long tube is analyzed. After the analysis is qualified, the main valve of the second long tube is opened, and the gas in the second long tube enters the hose in front of the main valve of the second long tube. The gas in the second long tube is used as the gas source, and the hose in front of the main valve of the second long tube is continuously replaced with positive pressure or vacuum replacement. After the replacement is completed, the gas in the hose in front of the main valve of the second long tube is analyzed again. After the analysis is qualified, the second long tube can be filled. If the analysis is unqualified, the second long tube cannot be filled. The first filling port and the second filling port are connected through a pressure equalizing pipeline, and the high-purity helium in the first long tube is filled into the second long tube through the pressure equalizing pipeline in a pressure equalizing manner one by one. At the same time, the high-purity helium in the high-purity helium buffer tank is pressurized by the compressor and filled into the second long tube through the second filling port; S3. The first long tube is also connected to a pressure reducing pipeline. The remaining high-purity helium in the first long tube is transported to a high-purity helium buffer tank through the pressure reducing pipeline, and then pressurized by a compressor and filled into the second long tube through the second filling port.

[0020] The specific method of positive pressure replacement is: the compressor outlet is also connected to the purge and cleaning pipeline, and the other end of the purge and cleaning pipeline is connected to the pressure equalizing pipeline. After the high-purity helium in the high-purity helium buffer tank is pressurized by the compressor, the high-purity helium is filled into the hose in front of the second long tube main valve through the purge and cleaning pipeline and the pressure equalizing pipeline until the pressure in the hose in front of the second long tube main valve reaches 1.0MPa, and then the gas in the hose in front of the second long tube main valve is recovered to the air bag through the recovery pipeline to complete a positive pressure replacement. Repeat the above steps to perform multiple positive pressure replacements on the hose in front of the second long tube main valve. After the replacement is completed, the gas in the hose in front of the second long tube main valve is sampled and analyzed through the analysis pipeline to analyze whether the gas in the hose in front of the second long tube main valve meets the requirements of GB / T4844-2011.

[0021] Generally speaking, after eight positive pressure replacements are performed on the hose in front of the second long tube main valve, the gas in the hose in front of the second long tube main valve is tested, which means that it meets the filling requirements of high-purity helium.

[0022] The above-mentioned positive pressure replacement method is to use the high-purity helium in the high-purity helium buffer tank as the gas source to perform positive pressure replacement on the hose in front of the second long tube main valve. The principle of using the gas in the second long tube as the gas source to perform positive pressure replacement on the hose in front of the second long tube main valve is the same as the above-mentioned positive pressure replacement.

[0023] The specific method of vacuum replacement is: vacuum the hose in front of the second long tube main valve through a vacuum pump and a vacuum pipeline until the vacuum degree in the hose in front of the second long tube main valve is <10Pa, and then the high-purity helium in the high-purity helium buffer tank is pressurized by a compressor, and then filled into the hose in front of the second long tube main valve through a purge and cleaning pipeline and a pressure equalization pipeline until the pressure in the hose in front of the second long tube main valve reaches 0.3MPa. At this time, the gas in the hose in front of the second long tube main valve is recovered into the airbag to complete a vacuum replacement, and the above steps are repeated to perform a second vacuum replacement on the hose in front of the second long tube main valve. After the replacement is completed, the gas in the hose in front of the second long tube main valve is sampled and analyzed through an analysis pipeline to analyze whether the gas in the hose in front of the second long tube main valve meets the requirements of GB / T4844-2011. Compared with positive pressure replacement, vacuum replacement consumes less high-purity helium.

[0024] The specific method of the above-mentioned vacuum replacement is to use the high-purity helium in the high-purity helium buffer tank as the gas source to vacuum replace the hose in front of the second long tube main valve. The principle of using the gas in the second long tube as the gas source to vacuum replace the hose in front of the second long tube main valve is the same as the above-mentioned vacuum replacement.

[0025] Preferably, the second long tube is connected to the second filling port through a hose, and the high-purity helium in the high-purity helium buffer tank is used as the gas source. During the vacuum replacement or positive pressure replacement of the hose in front of the second long tube main valve, the second long tube main valve is in a closed state.

[0026] The first long tube and the second long tube each include a plurality of tubes, and the specific method for evenly pressurizing the high-purity helium in the first long tubes into the second long tubes one by one is: filling one first long tube into the plurality of second long tubes in sequence, repeating the above steps, and filling the other first long tubes into the plurality of second long tubes in sequence.

[0027] The present invention also provides a BOG extraction high-purity helium filling device. In the BOG extraction high-purity helium filling method, the BOG extraction high-purity helium filling device is used to fill the second long tube 7, comprising a high-purity helium buffer tank 1, the outlet of the high-purity helium buffer tank 1 is connected to a compressor 2, the outlet of the compressor 2 is connected to a main filling pipeline 3, the other end of the main filling pipeline 3 is respectively connected to a first filling pipeline 4 and a second filling pipeline 5, the ends of the first filling pipeline 4 and the second filling pipeline 5 are respectively provided with a first filling port and a second filling port, the first filling port and the second filling port are respectively used to connect the first long tube 6 and the second long tube 7, a pressure equalizing pipeline 9 is connected between the first filling pipeline 4 and the second filling pipeline 5, and the second long tube is connected to the second filling port through a hose.

[0028] The inlet of the high-purity helium buffer tank 1 is connected with a pressure reducing pipeline 8, the end of the pressure reducing pipeline 8 is connected with the first long pipe 6, and a self-operated regulating valve is provided on the pressure reducing pipeline 8, which is the self-operated regulating valve PV03.

[0029] A pressure-maintaining valve 10 is provided on the main filling pipeline 3 at the outlet of the compressor 2. The working pressure of the pressure-maintaining valve 10 is 10.0 MPa. When the high-purity helium pressure at the outlet of the compressor 2 reaches 10.0 MPa, the pressure-maintaining valve 10 automatically opens to fill the first filling pipeline 4 and the second filling pipeline 5. A bypass valve V02 is also connected in parallel to the pressure-maintaining valve 10.

[0030] A purge and cleaning pipeline 11 is connected to the main filling pipeline 3, and the other end of the purge and cleaning pipeline 11 is connected to the pressure equalizing pipeline 9. A self-operated regulating valve is provided on the purge and cleaning pipeline 11, which is the self-operated regulating valve PV01. When positive pressure replacement or vacuum replacement is required, the high-purity helium pressurized by the compressor 2 passes through the purge and cleaning pipeline 11 and the pressure equalizing pipeline 9 and enters the hose in front of the main valve of the second long tube 7.

[0031] The first filling pipeline 4, the second filling pipeline 5 and the pressure reducing pipeline 8 are all connected with a vacuum pipeline 16, a recovery pipeline 13 and an analysis pipeline 12. A vacuum pump 17 is provided at the end of the vacuum pipeline 16, an air bag 14 is provided at the end of the recovery pipeline 13, and an analysis sampling port is provided at the end of the analysis pipeline 12. When vacuum replacement is performed, the vacuum pump 17 and the vacuum pipeline 16 are used to evacuate the hose in front of the main valve of the second long tube 7. The recovery pipeline 13 and the air bag 14 are used to recover the high-purity helium in the hose in front of the main valve of the second long tube. The analysis pipeline 12 and the analysis sampling port are used to sample and analyze the hose in front of the main valve of the second long tube 7.

[0032] A self-operated regulating valve PV02 is installed at the analysis sampling port.

[0033] The first filling pipeline 4 is also connected to a third filling pipeline 15 , and a third filling port is provided at the end of the third filling pipeline 15 . The third filling pipeline 15 is used to fill containers or loose bottles.

[0034] A check valve V07A and a check valve V07B are respectively provided at the positions where the first filling pipeline 4 and the second filling pipeline 5 are connected to the main filling pipeline 3, and a check valve V05 is provided on the purge and cleaning pipeline 11.

[0035] Stop valves are provided at the positions where the pressure equalizing pipeline 9 is connected to the first filling pipeline 4 and the second filling pipeline 5, namely stop valve V10A and stop valve V10B. A connecting pipeline is also connected to the pressure equalizing pipeline 9, and the other end of the connecting pipeline is connected to the pressure reducing pipeline 8. A stop valve V10C is provided on the connecting pipeline.

[0036] The three vacuum pipelines 16 are respectively provided with a stop valve V09A, a stop valve V09B and a stop valve V09C, the three recovery pipelines 13 are respectively provided with a stop valve V08A, a stop valve V08B and a stop valve V08C, and the three analysis pipelines 12 are respectively provided with a stop valve AE01A, a stop valve AE01B and a stop valve AE01C.

[0037] When a customer needs to fill high-purity helium, it is directly connected to the second filling port. After positive pressure replacement or vacuum replacement to meet the filling requirements, the high-purity helium in the first long tube is filled into the second long tube by pressure equalization. Then the remaining high-purity helium in the first long tube enters the high-purity helium buffer tank through the pressure reducing pipeline, and then is pressurized by the compressor and filled into the second long tube. This method shortens the filling time of the second long tube.

[0038] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for extracting high-purity helium from BOG, characterized in that: The following steps are involved: S1. The high-purity helium extracted from BOG is transported to a high-purity helium buffer tank. The high-purity helium in the high-purity helium buffer tank is pressurized by a compressor and then transported to a filling station. The filling station is provided with a first filling port and a second filling port. The first filling port and the second filling port are connected through a pressure-equalizing pipeline. The first filling port is connected to a first long tube. The high-purity helium is filled into the first long tube through the first filling port. S2. When the second long tube needs to be filled with high-purity helium, the second long tube is connected to the second filling port and connected to the pressure equalizing pipeline, and the high-purity helium pressurized by the compressor and the high-purity helium in the first long tube are both filled into the second long tube; S3. The first long tube is also connected to a pressure reducing pipeline, and the remaining high-purity helium in the first long tube is transported to the high-purity helium buffer tank through the pressure reducing pipeline, and then pressurized by a compressor and filled into the second long tube through the second filling port.

2. The method for extracting high-purity helium from BOG according to claim 1, characterized in that: In step S2, after the second long tube is connected to the second filling port, the high-purity helium in the high-purity helium buffer tank is used as the gas source to perform positive pressure replacement or vacuum replacement on the gas in the hose in front of the main valve of the second long tube. After the replacement is completed, the gas in the hose in front of the main valve of the second long tube is analyzed, and the second long tube is filled after the analysis is qualified.

3. The method for extracting high-purity helium from BOG according to claim 1, characterized in that: In step S2, a plurality of first long tubes and a plurality of second long tubes are provided, and the high-purity helium in the first long tube is filled into the second long tube in a tube-by-tube equalizing pressure manner, and the specific method is as follows: One first long tube is sequentially filled into a plurality of second long tubes, and the above steps are repeated to sequentially fill the other first long tubes into the plurality of second long tubes.

4. The method for extracting high-purity helium from BOG according to claim 1, characterized in that: The filling station is also provided with a third filling port, through which the container grid or the loose bottles are filled.

5. The method for extracting high-purity helium from BOG according to claim 1, characterized in that: The outlet of the compressor is provided with a pressure-maintaining valve, and the pressure of the pressure-maintaining valve is 10MPa.

6. The method for extracting high-purity helium from BOG according to claim 2, characterized in that: The steps of positive pressure displacement are: The compressor outlet is also connected to a purge and cleaning pipeline. After the high-purity helium in the high-purity helium buffer tank is pressurized by the compressor, the high-purity helium is filled into the hose in front of the second long tube main valve through the purge and cleaning pipeline until the pressure in the hose in front of the second long tube main valve reaches 1.0MPa, and then the gas in the hose in front of the second long tube main valve is recovered into the airbag to complete a positive pressure replacement. The above steps are repeated to perform positive pressure replacement on the hose in front of the second long tube main valve for multiple times until the hose in front of the second long tube main valve meets the filling standard.

7. The method for extracting high-purity helium from BOG according to claim 2, characterized in that: The steps of vacuum replacement are: The hose in front of the second long tube main valve is evacuated by a vacuum pump until the vacuum degree in the hose in front of the second long tube main valve is <10Pa, and then the high-purity helium in the high-purity helium buffer tank is pressurized by a compressor, and then filled into the hose in front of the second long tube main valve through the purge and clean pipeline until the pressure in the hose in front of the second long tube main valve reaches 0.3MPa. At this time, the gas in the hose in front of the second long tube main valve is recovered into the airbag to complete a vacuum replacement, and the above steps are repeated to perform a second vacuum replacement on the hose in front of the second long tube main valve until the hose in front of the second long tube main valve meets the filling standard.

8. The method for extracting high-purity helium from BOG according to claim 2, characterized in that: After the gas analysis in the hose in front of the second long tube main valve is qualified, open the second long tube main valve, and the gas in the second long tube enters the hose in front of the second long tube main valve. The gas in the second long tube is used as the gas source to perform vacuum replacement or positive pressure replacement on the hose in front of the second long tube main valve. After the replacement is completed, analyze the gas in the hose in front of the second long tube main valve again. After the analysis is qualified, the second long tube can be filled.

9. The method for extracting high-purity helium from BOG according to claim 8, characterized in that: The outlet of the high-purity helium buffer tank is connected to a compressor, and a main filling pipeline is provided at the outlet of the compressor, the main filling pipeline is connected to the first filling pipeline and the second filling pipeline respectively, and the first filling port and the second filling port are respectively arranged at the ends of the first filling pipeline and the second filling pipeline; The inlet of the pressure reducing pipeline is connected to the first long pipe, the outlet of the pressure reducing pipeline is connected to the high-purity helium buffer tank, and a self-operated regulating valve is arranged on the pressure reducing pipeline.

10. The method for extracting high-purity helium from BOG according to claim 9, characterized in that: The first filling pipeline, the second filling pipeline and the pressure reducing pipeline are all connected with a vacuum pipeline, a recovery pipeline and an analysis pipeline. The end of the vacuum pipeline is connected to a vacuum pump, the end of the recovery pipeline is connected to an air bag, and an analysis sampling port is arranged at the end of the analysis pipeline. A purge and cleaning pipeline is connected between the main filling pipeline and the pressure equalizing pipeline, and a self-operated regulating valve is arranged on the purge and cleaning pipeline.

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