Liquid argon storage device

Abstract

The utility model relates to a liquid argon storage device which comprises a main rectification tower and a compressed air conveying header pipe, and the main rectification tower comprises an upper tower, a main condensation evaporator and a lower tower, the compressed air conveying header pipe is provided with an inlet end of a first compressed air conveying branch pipe, a pressurizing end of a turbo expander, an inlet end of a second compressed air conveying branch pipe, a first regulating valve and an expansion end of the turbo expander, and a third compressed air conveying branch pipe is arranged between the expansion end of the turbo expander and the lower tower; a throttling valve and a heat exchanger are arranged on the second compressed air conveying branch pipe, a liquid argon storage tank is arranged below the heat exchanger, a liquid return pipe and a first pressure relief pipe are arranged between the liquid argon storage tank and the heat exchanger, a one-way valve is arranged on the liquid return pipe, and a first stop valve is arranged on the first pressure relief pipe. Argon stored on the top layer of the liquid argon storage tank can be emptied, liquefied and recycled; the utility model has the advantages of convenient use and wide market prospect.

Description

Technical Field

[0001] The utility model relates to the field of liquid argon storage equipment, in particular to a liquid argon storage device. Background Art

[0002] The five gases in the inert gas, argon, neon, helium, krypton, and xenon, are usually called "rare gases" in industry. They are named because of their rare content in the air. The content of argon is 0.93%, and the content of the other gases is 1×10 -4 In the following, krypton and xenon are called "golden gases" due to the difficulty of extraction and separation. Argon, like other gases, has extremely valuable chemical stability, so it is widely used in metal smelting, welding, semiconductor industry, scientific research and defense industry. As one of the mainstream processes for argon extraction, the hydrogenation and deoxygenation process is the main process for argon production introduced from Linde Company in Germany in the 1980s. It is divided into three parts: crude argon extraction, hydrogenation and deoxygenation, and purification of refined argon. After the argon fraction is distilled in the crude argon tower, the composition of crude argon is 90% to 95%, 1% to 2% oxygen components, and the rest is nitrogen components. The refined argon tower is used for the distillation and separation of nitrogen. Before entering the refined argon tower, 1% to 2% of the oxygen component in the crude argon must be removed. The crude argon coming out of the crude argon tower is hydrogenated and pressurized by the crude argon compressor. It is then catalyzed, cooled, and dried to become process argon containing only 1% to 4% of nitrogen components and 0.5% to 1% of hydrogen. Due to the large difference in the boiling points of argon and nitrogen and hydrogen, they are completely separated in the refined argon tower, and finally pure argon with a nitrogen content of less than 0.0001% is obtained.

[0003] In the process of metal smelting, argon blowing technology is an important measure to produce high-quality steel. The gas consumption for each ton of steel is about three cubic meters. Some stainless steel companies even consume fourteen cubic meters of gas per ton of steel. Steelmaking is the industry that consumes the most argon. Although steel production enterprises are generally equipped with cryogenic air separation systems, the load of the cryogenic air separation system of steel production enterprises is generally designed according to the general production capacity load of steel production enterprises. When steel production enterprises are in full-load production, there will still be a gap in argon demand, which requires the purchase of some argon products to fill the gap. Generally speaking, from the perspective of convenient transportation, the argon products purchased by steel production enterprises are in liquid form, with a temperature of minus 189.2 degrees to minus 185.9 degrees, and need to be filled into liquid argon storage tanks. During the filling process, when the low-temperature liquid argon is reduced to a saturation pressure corresponding to a temperature lower than the original liquid, part of the liquid will vaporize. This process is called "flash evaporation". The vaporized argon accumulates in the liquid argon storage tank, causing the internal pressure of the liquid argon storage tank to increase. In addition, during the normal storage of liquid argon, some of the liquid argon will be vaporized, and the vaporized argon will also cause the internal pressure of the liquid argon storage tank to increase. The increase in pressure inside the liquid argon storage tank will cause the tank body of the hydraulic storage tank to crack or explode, which is a safety hazard. If part of the vaporized argon in the liquid argon storage tank is discharged, it will also cause a waste of argon. Taking the commercially available liquid argon storage tank as an example, when the pressure at the top of the liquid argon storage tank reaches 15kPa, the safety valve of the liquid argon storage tank automatically opens, and the vaporized argon is partially discharged from the liquid argon storage tank to maintain the safety pressure in the liquid argon storage tank. The process is measured to release about 200 cubic meters of argon per hour, resulting in a large amount of argon waste. Therefore, for steel production enterprises, there is room for improvement from the perspective of the safety of the use of liquid argon storage tanks and the cost of liquid argon storage. Under the premise of ensuring the safety of the use of liquid argon storage tanks, the consumption caused by normal argon storage can be reduced as much as possible, thereby reducing the operating costs of the enterprise. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a liquid argon storage device capable of evacuating and liquefying the argon gas stored in the top layer of a liquid argon storage tank and then recovering it, so as to overcome the defects in the prior art.

[0005] The technical solution adopted by the utility model is: a liquid argon storage device, including a main distillation tower and a compressed air delivery main pipe, the main distillation tower includes an upper tower, a main condenser evaporator and a lower tower from top to bottom, the compressed air delivery main pipe is sequentially provided with an inlet end of a first compressed air delivery branch pipe, a booster end of a turbine expander, an inlet end of a second compressed air delivery branch pipe, a first regulating valve and an expansion end of the turbine expander, the expansion end of the turbine expander and the lower tower in a direction from the inlet end close to the compressed air delivery main pipe to the inlet end far away from the compressed air delivery main pipe. A third compressed air delivery branch pipe is provided between the towers, the outlet end of the first compressed air delivery branch pipe is connected to the upper tower, a throttle valve is provided on the second compressed air delivery branch pipe, a cold source channel of a heat exchanger is provided on the outlet end of the second compressed air delivery branch pipe, a liquid argon storage tank is provided below the heat exchanger, the top of the liquid argon storage tank and the outlet end of the heat source channel of the heat exchanger are connected through a liquid reflux pipe, a one-way valve is provided on the liquid reflux pipe, the top of the liquid argon storage tank and the inlet end of the heat source channel of the heat exchanger are connected through a first pressure relief pipe, and a first stop valve is provided on the first pressure relief pipe.

[0006] Preferably, a main heat exchanger is arranged on the compressed air delivery main pipe between the first regulating valve and the expansion end of the turbine expander, the first compressed air delivery branch pipe and the second compressed air delivery branch pipe, the first compressed air delivery branch pipe and the second compressed air delivery branch pipe are respectively provided with a second regulating valve, and a fourth compressed air delivery branch pipe is arranged between the top of the heat exchanger cold source channel and the upper tower.

[0007] Preferably, the fourth compressed air delivery branch pipe is provided with a first pressure sensor, a third regulating valve and a second pressure sensor in sequence along a direction from close to the upper tower to far away from the upper tower.

[0008] Preferably, a liquid argon delivery pipe is provided at the bottom of the liquid argon storage tank, a second stop valve is provided on the liquid argon delivery pipe, the first pressure relief pipes on both sides of the first stop valve are connected through the second pressure relief pipe, and a self-supporting regulating valve is provided on the second pressure relief pipe.

[0009] Preferably, a third pressure sensor is provided on the first pressure relief pipe between the second pressure relief pipe and the liquid argon storage tank.

[0010] Preferably, the heat source channel of the heat exchanger is located inside the cold source channel of the heat exchanger, and part of the heat source channel of the heat exchanger adopts a spiral tubular structure.

[0011] Preferably, liquid level sensors are respectively provided at the bottom of the lower tower, the liquid argon storage tank and the cold source channel of the heat exchanger.

[0012] The beneficial effects of the utility model are as follows: firstly, the utility model makes full use of the air separation and distillation system in the steel production enterprise, and utilizes the liquid air formed by the throttled compressed air to indirectly exchange heat with the vaporized argon gas in the heat exchanger, thereby completing the process in which the vaporized argon gas is liquefied again and refluxed to the liquid argon storage tank, thereby improving the use safety of the liquid argon storage tank, and at the same time, the vaporized liquid air is sent to the upper tower to participate in the distillation of the upper tower, further reducing the waste of raw materials.

[0013] Secondly, a third pressure sensor is arranged on the first pressure relief pipe between the second pressure relief pipe and the liquid argon storage tank in the utility model; the installation of the third pressure sensor facilitates the feedback of the pressure parameters at the top of the liquid argon storage tank.

[0014] Thirdly, the bottom of the lower tower, the liquid argon storage tank and the cold source channel of the heat exchanger described in the utility model are respectively provided with liquid level sensors; the installation of the liquid level sensors facilitates the feedback of liquid level parameters.

[0015] The utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improved working efficiency, good social and economic benefits, and is a product that is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 for Figure 1 A partial enlarged schematic diagram of detail A. DETAILED DESCRIPTION

[0018] like Figure 1 to Figure 2As shown, a liquid argon storage device comprises a main distillation tower and a compressed air delivery main pipe 1, wherein the main distillation tower comprises an upper tower 2, a main condenser evaporator 3 and a lower tower 4 from top to bottom, and the compressed air delivery main pipe 1 is provided with an inlet end of a first compressed air delivery branch pipe 5, a boost end of a turbine expander 6, an inlet end of a second compressed air delivery branch pipe 7, a first regulating valve 8 and an expansion end of the turbine expander 6 in sequence along a direction from an inlet end close to the compressed air delivery main pipe 1 to an inlet end far from the compressed air delivery main pipe 1, and a third compressed air delivery branch pipe 7 is provided between the expansion end of the turbine expander 6 and the lower tower 4. 9, the outlet end of the first compressed air delivery branch pipe 5 is connected to the upper tower 2, the second compressed air delivery branch pipe 7 is provided with a throttle valve 10, the outlet end of the second compressed air delivery branch pipe 7 is provided with a cold source channel of the heat exchanger 11, a liquid argon storage tank 12 is provided below the heat exchanger 11, the top of the liquid argon storage tank 12 and the outlet end of the heat source channel of the heat exchanger 11 are connected through a liquid reflux pipe 13, a one-way valve 14 is provided on the liquid reflux pipe 13, the top of the liquid argon storage tank 12 and the inlet end of the heat source channel of the heat exchanger 11 are connected through a first pressure relief pipe 15, and the first pressure relief pipe 15 is provided with a first stop valve 16. A main heat exchanger 17 is arranged on the compressed air delivery main pipe 1 between the first regulating valve 8 and the expansion end of the turbine expander 6, the first compressed air delivery branch pipe 5 and the second compressed air delivery branch pipe 7. The first compressed air delivery branch pipe 5 and the second compressed air delivery branch pipe 7 are respectively provided with a second regulating valve 18. A fourth compressed air delivery branch pipe 19 is arranged between the top of the cold source channel of the heat exchanger 11 and the upper tower 2. The upper tower 2 and the lower tower 4 are connected through an oxygen-enriched liquid air delivery pipe 20. The top of the upper tower 2 and the inlet end of the heat source channel of the main condenser evaporator 3 are connected through a pressurized nitrogen delivery pipe 21. A liquid nitrogen delivery main pipe 22 is arranged on the outlet end of the heat source channel of the main condenser evaporator 3. The liquid nitrogen delivery main pipe 22 is provided with the inlet end of the first liquid nitrogen delivery branch pipe 23, the inlet end of the second liquid nitrogen delivery branch pipe 24 and the fourth regulating valve 25 in sequence in the direction from close to the main condenser evaporator 3 to far away from the main condenser evaporator 3. The outlet end of the first liquid nitrogen delivery branch pipe 23 is connected to the lower tower 4. The outlet ends of the second liquid nitrogen delivery branch pipes 24 are connected to the upper tower 2, and the oxygen-enriched liquid air delivery pipe 20, the first liquid nitrogen delivery branch pipe 23 and the second liquid nitrogen delivery branch pipe 24 are respectively provided with a fifth regulating valve 26, the lower tower 4 and the main heat exchanger 17 are provided with a dirty nitrogen delivery pipe 27 and an oxygen delivery pipe 28, the liquid nitrogen delivery main pipe 22 between the first liquid nitrogen delivery branch pipe 23 and the second liquid nitrogen delivery branch pipe 24, the oxygen-enriched liquid air delivery pipe 20 and the dirty nitrogen delivery pipe 27 are provided with a subcooler 29, and the lower tower 4 is provided with a liquid argon distillation extraction pipe 30 and a liquid argon distillation reflux pipe 31.

[0019] The fourth compressed air delivery branch pipe 19 is provided with a first pressure sensor 32, a third regulating valve 33 and a second pressure sensor 34 in sequence along the direction from close to the upper tower 2 to far away from the upper tower 2. The third regulating valve 33 is installed to facilitate the adjustment of the pressure parameters of the vaporized liquid air delivered to the upper tower 2, and the first pressure sensor 32 and the second pressure sensor 34 are installed to facilitate the feedback of the pressure parameters.

[0020] The number of liquid argon storage tanks 12 is several, and a liquid reflux pipe 13, a first pressure relief pipe 15 and a heat exchanger 11 are correspondingly installed on the top of each liquid argon storage tank 12, and a one-way valve 14 is correspondingly installed on each liquid reflux pipe 13; the cold source channel of each heat exchanger 11 is connected to the outlet end of the second compressed air delivery branch pipe 7; a liquid argon delivery pipe 35 is respectively provided at the bottom of each liquid argon storage tank 12, and a second stop valve 36 is respectively provided on each liquid argon delivery pipe 35, and the first pressure relief pipes 15 on both sides of the first stop valve 16 are connected through the second pressure relief pipe 37, and a self-supporting regulating valve 38 is provided on the second pressure relief pipe 37. The self-supporting regulating valve 38 includes a self-supporting regulating valve body and a pressure-taking pipe. The second pressure relief pipe 37 between the self-supporting regulating valve body of the self-supporting regulating valve 38 and the liquid argon storage tank 12 is connected to the pressure-taking pipe of the self-supporting regulating valve 38. A third pressure sensor 39 is provided on the first pressure relief pipe 15 between the second pressure relief pipe 37 and the liquid argon storage tank 12. The installation of the third pressure sensor 39 facilitates the feedback of the pressure parameters at the top of the liquid argon storage tank 12.

[0021] The heat source channel of the heat exchanger 11 is located inside the cold source channel of the heat exchanger 11, and part of the heat source channel of the heat exchanger 11 adopts a spiral tubular structure. Liquid level sensors 40 are respectively arranged at the bottom of the lower tower 4, the liquid argon storage tank 12 and the cold source channel of the heat exchanger 11.

[0022] The usage of this product is as follows: Figure 1 to Figure 2 As shown, the following steps are included:

[0023] S1, the compressed air after adsorption purification delivered by the upstream purification system is delivered to the compressed air delivery main pipe 1 and then divided into two parts, namely the first part of compressed air and the second part of compressed air. The first part of compressed air enters the first compressed air delivery branch pipe 5 and then enters the first heat source channel of the main heat exchanger 17 and the cold source entering the main heat exchanger 17 for heat exchange, and then continues to move forward along the first compressed air delivery branch pipe 5 to be delivered to the lower tower 4 as the distillation raw material of the lower tower 4; the second part of compressed air continues to move forward along the compressed air delivery main pipe 1 and is then pressurized again by the boosting end of the turbine expander 6 and is again divided into two parts, namely the third part of compressed air and the fourth part of compressed air; the second part of compressed air enters the second heat source channel of the main heat exchanger 17 and the cold source entering the main heat exchanger 17 for heat exchange, and then moves from the high pressure of the main heat exchanger 17 to the high pressure of the main heat exchanger 17. The third part of the compressed air after expansion and cooling enters the upper tower 2 through the third compressed air delivery branch pipe 9 as one of the gaseous distillation raw materials of the upper tower 2; the fourth part of the compressed air enters the first compressed air delivery branch pipe 5 and then enters the third heat source channel of the main heat exchanger 17 and the cold source entering the main heat exchanger 17 for heat exchange, and then continues along the first compressed air delivery branch pipe 5 and is throttled by the throttle valve 10 to be liquefied to form liquid air and delivered to the cold source channel of the heat exchanger 11. The liquid air in the cold source channel of the heat exchanger 11 and the medium entering the heat source channel of the heat exchanger 11 are vaporized after heat exchange to form the fifth part of compressed air and enter the upper tower 2 through the fourth compressed air delivery branch pipe 19 as one of the gaseous distillation raw materials of the upper tower 2.

[0024] S2, the first part of the compressed air in the lower tower 4 forms a first ascending airflow and continues to ascend along the lower tower 4 and performs countercurrent heat exchange with the reflux condensate of the lower tower 4, the oxygen component in the first ascending airflow is liquefied and descends together with the reflux condensate of the lower tower 4 to form an oxygen-rich liquid air enrichment zone at the bottom of the lower tower 4; the nitrogen component in the reflux condensate of the lower tower 4 is vaporized and continues to ascend along with the first ascending airflow and finally forms a high-pressure nitrogen enrichment zone at the top of the lower tower 4; the high-pressure nitrogen in the high-pressure nitrogen enrichment zone is transported to the heat source channel of the main condenser evaporator 3 and continuously transported to the cold source of the cold source channel of the main condenser evaporator 3 through the pressure nitrogen delivery pipe 21, and then liquefied to form liquid nitrogen and transported to the liquid nitrogen delivery main pipe 22 through the outlet end of the heat source channel of the main condenser evaporator 3. The liquid nitrogen entering the liquid nitrogen delivery main pipe 22 is first divided into two parts, namely the first part of liquid nitrogen and the second part of liquid nitrogen. The first part of liquid nitrogen is sent back to the lower tower 4 through the first liquid nitrogen delivery branch pipe 23 as the reflux condensate of the lower tower 4; the second part of liquid nitrogen continues to go along the liquid nitrogen delivery main pipe 22 and then enters the first heat source channel of the subcooler 29 and exchanges heat with the cold source continuously sent to the subcooler 29 to form subcooled liquid nitrogen, and the subcooled liquid nitrogen is again divided into two parts, namely the first part of subcooled liquid nitrogen and the second part of subcooled liquid nitrogen. The first part of subcooled liquid nitrogen continues to go along the liquid nitrogen delivery main pipe 22 and is discharged to the liquid nitrogen storage device through the liquid nitrogen delivery main pipe 22 for collection; the second part of subcooled liquid nitrogen is delivered to the second liquid nitrogen delivery branch pipe 24 through the second liquid nitrogen delivery branch pipe 24 as the first reflux condensate of the upper tower 2; the oxygen-rich liquid air enrichment zone is delivered to the upper tower 2 through the oxygen-rich liquid air delivery pipe 20 as the second reflux condensate of the upper tower 2 and as the liquid distillation raw material of the upper tower 2.

[0025] S3, the gaseous distillation raw materials entering the upper tower 2 are combined to form a second ascending airflow and continue to ascend along the inner cavity of the upper tower 2, the second ascending airflow first performs countercurrent heat exchange with the second reflux condensate of the upper tower 2, the nitrogen component in the second reflux condensate of the upper tower 2 is vaporized and ascends together with the second ascending airflow, while the oxygen component in the second ascending airflow is liquefied and descends together with the second reflux condensate of the upper tower 2 to form a first descending liquid flow; after the second ascending airflow continues to ascend, it encounters the first reflux condensate of the upper tower 2 for countercurrent heat exchange again, the residual oxygen component of the second ascending airflow is liquefied by the first reflux condensate of the upper tower 2 and descends together with the first reflux condensate to form a second descending liquid flow, the second descending liquid flow is combined with the first descending liquid flow during the descending process to form a third descending liquid flow, and the first descending liquid flow of the upper tower 2 is liquefied. The nitrogen component in the reflux condensate is vaporized in large quantities and enriched at the top of the upper tower 2 along with the second rising air flow to form a low-pressure nitrogen enrichment zone. The part of the low-pressure nitrogen enrichment zone containing non-condensable gas is output together with the low-pressure nitrogen to form dirty nitrogen; the remaining part can be produced as finished low-pressure nitrogen to the outside. The finished nitrogen production pipe is not shown in the figure, and the third descending liquid flow continues to descend into the cold source channel of the main condenser evaporator 3. A large amount of nitrogen components in the third descending liquid flow entering the cold source channel of the main condenser evaporator 3 continue to ascend along with a small amount of oxygen components to form a third rising airflow. The third rising airflow and the third descending liquid flow are subjected to countercurrent heat exchange, and finally a finished oxygen enrichment zone is formed at the bottom of the upper tower 2, and the part of the third rising airflow that continues to ascend is merged in the second rising airflow and ascends together to participate in the heat exchange process of the second rising airflow.

[0026] S4, the finished oxygen in the finished oxygen enrichment zone is transported to the target user through the oxygen delivery pipe 28, during which heat is exchanged through the first cold source channel of the main heat exchanger 17 and the heat source of the continuous delivery pipe main heat exchanger 17; the dirty nitrogen enters the dirty nitrogen delivery pipe 27, and the dirty nitrogen entering the dirty nitrogen delivery pipe 27 first enters the cold source channel of the subcooler 29 and the heat source continuously delivered to the subcooler 29 for heat exchange, and then is sent to the second cold source channel of the main heat exchanger 17 and the heat source of the continuous delivery pipe main heat exchanger 17 for heat exchange, and then is transported out through the outlet end of the dirty nitrogen delivery pipe 27; part of the third descending liquid flow is transported to the liquid argon distillation system through the liquid argon distillation extraction pipe 30 to separate the liquid argon part, and the residual liquid phase component after the argon component is separated in the liquid argon distillation system is again sent back to the lower tower 4 through the liquid argon distillation reflux pipe 31 and merged with the continuously descending third descending liquid flow again.

[0027] S5. The liquid argon produced in the liquid argon distillation system or purchased liquid argon is transported to the liquid argon storage tank 12 to be received by the liquid argon delivery pipe 35. During this period, the first stop valve 16 needs to be opened. The original argon gas in the liquid argon storage tank 12 is transported to the heat source channel of the heat exchanger 11 and the cold source in the heat exchanger 11 through the first pressure relief pipe 15 for heat exchange. The argon gas is liquefied again during the transportation through the heat source channel of the heat exchanger 11 and enters the liquid reflux pipe 13 through the outlet end of the heat source channel of the heat exchanger 11 and finally flows back to the liquid argon storage tank 12 again, thereby reducing the technical problem that too much argon gas is vaporized in the liquid argon storage tank 12 to be received, resulting in excessive pressure in the liquid argon storage tank 12 and difficulty in the entry of liquid argon. In addition, the liquid argon storage tank 12 in the storage state is continuously evaporated, resulting in the pressure of the upper layer of the liquid argon storage tank 12 in the storage state continuously increasing. When the pressure of the upper layer of the liquid argon storage tank 12 in the storage state increases to a preset range, the self-supporting regulating valve 38 on the second pressure relief pipe 37 is automatically opened. At this time, the vaporized argon gas in the upper layer of the liquid argon storage tank 12 in the storage state enters the heat source channel of the heat exchanger 11 through the second pressure relief pipe 37. The medium in the cold source channel of the heat exchanger 11 is liquefied after heat exchange and then returns to the liquid argon storage tank 12 again, thereby reducing the technical problem of the continuous increase of the pressure in the upper layer of the liquid argon storage tank 12.

[0028] Through this embodiment, the air separation and distillation system in the steel production enterprise is fully utilized, and the liquid air formed by the throttled compressed air is indirectly heat exchanged with the vaporized argon gas in the heat exchanger 11, so that the vaporized argon gas is liquefied again and refluxed to the liquid argon storage tank, thereby improving the safety of the liquid argon storage tank. At the same time, the vaporized liquid air is sent to the upper tower 2 to participate in the distillation of the upper tower 2, further reducing the waste of raw materials.

[0029] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made based on the structures, features and principles described in the patent scope of the present invention should be included in the patent application scope of the present invention.

Claims

1. A liquid argon storage device, comprising a main distillation tower and a compressed air delivery main pipe (1), wherein the main distillation tower comprises, from top to bottom, an upper tower (2), a main condenser evaporator (3) and a lower tower (4), characterized in that: The compressed air delivery main pipe (1) is provided with an inlet end of a first compressed air delivery branch pipe (5), a boosting end of a turbine expander (6), an inlet end of a second compressed air delivery branch pipe (7), a first regulating valve (8) and an expansion end of the turbine expander (6) in sequence along a direction from an inlet end of the compressed air delivery main pipe (1) to an inlet end far from the compressed air delivery main pipe (1). A third compressed air delivery branch pipe (9) is provided between the expansion end of the turbine expander (6) and the lower tower (4). The outlet end of the first compressed air delivery branch pipe (5) is connected to the upper tower (2). The outlet end of the second compressed air delivery branch pipe (7) is connected to the upper tower (2). A throttle valve (10) is provided on the delivery branch pipe (7), a cold source channel of the heat exchanger (11) is provided on the outlet end of the second compressed air delivery branch pipe (7), a liquid argon storage tank (12) is provided below the heat exchanger (11), the top of the liquid argon storage tank (12) and the outlet end of the heat source channel of the heat exchanger (11) are connected via a liquid return pipe (13), a one-way valve (14) is provided on the liquid return pipe (13), the top of the liquid argon storage tank (12) and the inlet end of the heat source channel of the heat exchanger (11) are connected via a first pressure relief pipe (15), and a first stop valve (16) is provided on the first pressure relief pipe (15).

2. The liquid argon storage device according to claim 1, characterized in that: A main heat exchanger (17) is provided on the compressed air delivery main pipe (1) between the first regulating valve (8) and the expansion end of the turbine expander (6), the first compressed air delivery branch pipe (5) and the second compressed air delivery branch pipe (7); the first compressed air delivery branch pipe (5) and the second compressed air delivery branch pipe (7) are each provided with a second regulating valve (18); and a fourth compressed air delivery branch pipe (19) is provided between the top end of the cold source channel of the heat exchanger (11) and the upper tower (2).

3. The liquid argon storage device according to claim 2, characterized in that: The fourth compressed air delivery branch pipe (19) is provided with a first pressure sensor (32), a third regulating valve (33) and a second pressure sensor (34) in sequence along a direction from close to the upper tower (2) to far away from the upper tower (2).

4. The liquid argon storage device according to claim 1, characterized in that: A liquid argon delivery pipe (35) is provided at the bottom of the liquid argon storage tank (12), a second stop valve (36) is provided on the liquid argon delivery pipe (35), the first pressure relief pipes (15) on both sides of the first stop valve (16) are connected through a second pressure relief pipe (37), and a self-supporting regulating valve (38) is provided on the second pressure relief pipe (37).

5. The liquid argon storage device according to claim 4, characterized in that: A third pressure sensor (39) is provided on the first pressure relief pipe (15) between the second pressure relief pipe (37) and the liquid argon storage tank (12).

6. The liquid argon storage device according to claim 1, characterized in that: The heat source channel of the heat exchanger (11) is located on the inner side of the cold source channel of the heat exchanger (11), and part of the heat source channel of the heat exchanger (11) adopts a spiral tubular structure.

7. The liquid argon storage device according to claim 1, characterized in that: Liquid level sensors (40) are respectively arranged at the bottom of the lower tower (4), the liquid argon storage tank (12) and the cold source channel of the heat exchanger (11).

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