Air separation device

Abstract

The utility model relates to the field of air separation equipment, and discloses an air separation device which comprises an air separation tower, a cold charging pipe and a cold charging module, the air separation tower comprises an upper tower and a lower tower which are sequentially connected, a condensation evaporator is arranged between the upper tower and the lower tower, the evaporation side of the condensation evaporator is arranged at the bottom in the upper tower, and the condensation side of the condensation evaporator is arranged at the top in the lower tower; an outlet of the cold filling pipe is connected with the bottom of the upper tower; the cold filling module is connected with an inlet of the cold filling pipe and is used for supplying output liquid of the air separation tower into the cold filling pipe in the liquid accumulation stage; the air separation tower output liquid is filled into the inner bottom of the upper tower through the cold filling pipe, and after the filled air separation tower output liquid is accumulated to a certain amount at the inner bottom of the upper tower, the condensation evaporator can start to work, equivalently, the process of condensation and liquid accumulation on the evaporation side of the condensation evaporator in the prior art is omitted, the liquid accumulation time is shortened, the starting speed is increased, and the working efficiency is improved. Power consumption is not needed, and the overall operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of air separation equipment, and more specifically, to an air separation device. Background Art

[0002] The air separation unit is mainly used to process and separate air. Its principle is to liquefy and distill air at room temperature to obtain gaseous and liquid products such as oxygen, nitrogen, and argon. The hot start-up of the air separation unit needs to go through four stages, namely heating and purging, cooling, liquid accumulation, and purification. In theory, the four stages take about 40 hours (the specific time varies depending on the size of the air separation unit). There is no product output in the first three stages. If the time required can be shortened, the equipment efficiency can be greatly improved. When liquid appears on the evaporation side of the condenser evaporator, the cooling stage ends and the liquid accumulation stage begins. The liquid needs to accumulate to a certain amount before the condenser evaporator can gradually enter the working state. The liquid accumulation process requires the air compressor to run at full load. For medium and large air separation units, its power consumption is quite amazing. The liquid accumulation stage generally takes about ten or twenty hours, and has a large operating space.

[0003] The invention patent application with application publication number CN109974394A discloses an air separation device and a method for liquid accumulation in the start-up stage thereof. The air separation device provided by the invention comprises an air separation tower, the air separation tower comprises a lower tower and an upper tower, the upper tower is provided with a liquid nitrogen inlet, an air inlet, a liquid air inlet, a liquid phase outlet and a plurality of gas phase outlets, the position of the liquid nitrogen inlet is higher than the air inlet; an air conveying pipeline connected to the air inlet; a liquid nitrogen conveying pipeline connected to the liquid nitrogen inlet; when the air separation device is started, liquid nitrogen and air are respectively input into the upper tower of the air separation tower through corresponding conveying pipelines, and condensation of rising air and gasification of liquid nitrogen are realized on each tower plate, and the condensed liquid flows to the bottom of the upper tower to form liquid accumulation.

[0004] The above scheme mainly connects liquid nitrogen and air in the upper tower, the liquid nitrogen vaporizes and absorbs heat, and the air is condensed and flows down to the bottom of the upper tower, thereby accelerating the accumulation of liquid. However, this method still requires that the liquid condensed from the liquid nitrogen accumulates to a certain amount at the bottom of the upper tower before the condensing evaporator can work. The process of condensation and liquid accumulation takes a long time, resulting in a slow overall startup speed and high power consumption. Utility Model Content

[0005] The utility model aims to overcome the defects of the above-mentioned prior art and provide an air separation device for solving the technical problems that the condensed liquid must be continuously accumulated to a certain amount at the bottom of the upper tower before the condenser evaporator can work, and the process of condensation and liquid accumulation takes a long time, resulting in a slow overall startup speed and high power consumption.

[0006] The technical solution adopted by the utility model is an air separation device, comprising an air separation tower, a cold charging pipe and a cold charging module; the air separation tower comprises an upper tower and a lower tower connected in sequence, a condenser evaporator is arranged between the upper tower and the lower tower, the evaporation side of the condenser evaporator is arranged at the bottom of the upper tower, and the condensation side of the condenser evaporator is arranged at the top of the lower tower; the cold charging pipe outlet is connected to the bottom of the upper tower; the cold charging module is connected to the cold charging pipe inlet, and is used to supply the air separation tower output liquid into the cold charging pipe during the liquid accumulation stage.

[0007] During the liquid accumulation stage, the output liquid of the air separation tower is supplied to the cold charging pipe through the cold charging module, and the output liquid of the air separation tower is filled into the bottom of the upper tower through the cold charging pipe. After the output liquid of the air separation tower is accumulated to a certain amount at the bottom of the upper tower, the condenser evaporator can start working, which is equivalent to eliminating the process of condensation and liquid accumulation on the evaporation side of the condenser evaporator in the prior art, shortening the liquid accumulation time, accelerating the startup speed, eliminating the need for electricity consumption, and reducing the overall operating cost.

[0008] Furthermore, a low temperature stop valve is provided between the cold charging module and the cold charging pipe inlet, the low temperature stop valve inlet is detachably connected to the cold charging module, and the low temperature stop valve outlet is fixedly connected to the cold charging pipe inlet. After the liquid accumulation is completed, the cold charging pipe is cut off by the low temperature stop valve, so that the upper tower and the lower tower can operate normally.

[0009] Furthermore, the cold charging module is connected with a hose for outputting the output liquid of the air separation tower, and the hose is connected to the inlet of the low-temperature stop valve through a quick connector. The hose can be bent arbitrarily, which is more convenient to use. The quick connector is easy to connect and disconnect quickly, which can effectively shorten the connection time, improve the connection efficiency, and provide a better user experience.

[0010] Furthermore, the cold charging module is an air separation tower output liquid storage tank or tank car with a pressurizing device. The air separation tower output liquid storage tank or tank car stores a large amount of air separation tower output liquid. When liquid accumulates, the air separation tower output liquid can be quickly charged into the bottom of the upper tower, requiring a short time and a fast charging time.

[0011] Furthermore, the output liquid of the air separation tower is liquid nitrogen or liquid oxygen. When the air separation device is operating normally, the liquid produced at the bottom of the upper tower is liquid oxygen. If the output liquid of the air separation tower charged into the bottom of the upper tower is liquid oxygen, it is equivalent to directly transitioning the upper tower to a normal operating state after liquid accumulation; if the output liquid of the air separation tower charged into the bottom of the upper tower is liquid nitrogen, its cooling capacity is greater than that of liquid oxygen, and its safety is better, and the condenser evaporator can also enter a working state.

[0012] Furthermore, a liquid oxygen extraction pipe is provided at the bottom of the upper tower, a valve 2 is provided on the liquid oxygen extraction pipe, a liquid oxygen discharge pipe is connected to the liquid oxygen extraction pipe between the valve 2 and the upper tower, a valve 1 is provided on the liquid oxygen discharge pipe, and the outlet of the cold charging pipe is connected to the liquid oxygen discharge pipe between the valve 1 and the liquid oxygen extraction pipe. By utilizing the liquid oxygen extraction pipe and the liquid oxygen discharge pipe, there is no need for cold box sand removal and high-altitude operations during implementation, which can effectively reduce costs.

[0013] Furthermore, a nitrogen discharge pipe, a dirty nitrogen discharge pipe, an argon fraction gas discharge pipe and an oxygen discharge pipe are sequentially arranged from the top of the upper tower body downward, and the position of the oxygen discharge pipe is higher than the position of the liquid oxygen extraction pipe. The nitrogen discharge pipe, the dirty nitrogen discharge pipe, the argon fraction gas discharge pipe and the oxygen discharge pipe are used to output nitrogen, dirty nitrogen, argon fraction gas and oxygen respectively, and the liquid oxygen extraction pipe is used to output liquid oxygen.

[0014] Further, the lower tower is provided with a liquid nitrogen reflux pipe, the liquid nitrogen reflux pipe has a first end and a second end, the first end of the liquid nitrogen reflux pipe is used to connect the liquid nitrogen receiving tank provided at the top of the lower tower, the second end of the liquid nitrogen reflux pipe is connected to the top of the lower tower, the height of the second end of the liquid nitrogen reflux pipe is less than the height of the first end of the liquid nitrogen reflux pipe, and a valve is provided on the liquid nitrogen reflux pipe. The air separation tower is provided with a liquid nitrogen delivery pipe, one end of the liquid nitrogen delivery pipe is connected to the liquid nitrogen reflux pipe, and the other end of the liquid nitrogen delivery pipe is connected to the top of the upper tower. The liquid nitrogen reflux pipe refluxes a part of the liquid nitrogen in the liquid nitrogen receiving tank into the lower tower as the reflux liquid of the lower tower, and the other part is input into the upper tower through the liquid nitrogen delivery pipe as the reflux liquid of the top distillation section in the upper tower.

[0015] Furthermore, the air separation tower is provided with a liquid air delivery pipe, the bottom of the lower tower is connected to the middle and upper part of the upper tower through the liquid air delivery pipe, and the middle and lower part of the lower tower is connected to a compressed air delivery pipe. The compressed air delivery pipe is mainly used to deliver compressed air to the lower tower, and the liquid air delivery pipe is used to deliver the liquid air at the bottom of the lower tower to the middle and upper part of the upper tower.

[0016] Compared with the prior art, the beneficial effects of the utility model are as follows: in the liquid accumulation stage, the output liquid of the air separation tower is supplied to the cold charging pipe through the cold charging module, and the output liquid of the air separation tower is filled into the bottom of the upper tower through the cold charging pipe. After the output liquid of the air separation tower is accumulated to a certain amount at the bottom of the upper tower, the condenser evaporator can start working, which is equivalent to eliminating the process of condensation and liquid accumulation on the evaporation side of the condenser evaporator in the prior art, shortening the liquid accumulation time, accelerating the startup speed, eliminating the need for electricity consumption, and reducing the overall operating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0018] In the figure: 1, air separation tower, 2, cold charging pipe, 3, low-temperature stop valve, 4, upper tower, 5, lower tower, 6, condenser evaporator, 7, liquid oxygen removal pipe, 8, cold charging module, 9, hose, 10, quick connector, 11, oxygen discharge pipe, 12, liquid nitrogen reflux pipe, 13, liquid nitrogen delivery pipe, 14, nitrogen discharge pipe, 15, dirty nitrogen discharge pipe, 16, argon fraction gas discharge pipe, 17, liquid air delivery pipe, 18, compressed air delivery pipe, 19, liquid oxygen discharge pipe, 20, valve one, 21, valve two, 22, cooling pipe, 23, stop valve, 24, cold charging mechanism, 25, throttle valve. DETAILED DESCRIPTION

[0019] The drawings of the present invention are only used for illustrative purposes and cannot be construed as limiting the present invention. In order to better illustrate the following embodiments, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0020] like Figure 1 As shown, the present scheme discloses an air separation device, including an air separation tower 1 and a cold charging mechanism 24.

[0021] The air separation tower 1 includes an upper tower 4 and a lower tower 5 which are connected in sequence, a condenser evaporator 6 is arranged between the upper tower 4 and the lower tower 5, the evaporation side of the condenser evaporator 6 is arranged at the bottom of the upper tower 4, and the condensation side of the condenser evaporator 6 is arranged at the top of the lower tower 5; a nitrogen exhaust pipe 14, a dirty nitrogen exhaust pipe 15, an argon distillate exhaust pipe 16, an oxygen exhaust pipe 11 and a liquid oxygen extraction pipe 7 are arranged in sequence from top to bottom on the upper tower 4.

[0022] The lower tower 5 is provided with a compressed air delivery pipe 18, and the bottom of the lower tower 5 is connected to the middle and upper part of the upper tower 4 through a liquid air delivery pipe 17; the lower tower 5 is provided with a liquid nitrogen reflux pipe 12, and the liquid nitrogen reflux pipe 12 has a first end and a second end. The first end of the liquid nitrogen reflux pipe 12 is used to connect to the liquid nitrogen receiving tank arranged at the top of the lower tower 5, and the second end of the liquid nitrogen reflux pipe 12 is connected to the top of the lower tower 5. The height of the second end of the liquid nitrogen reflux pipe 12 is less than the height of the first end of the liquid nitrogen reflux pipe 12, and a valve is arranged on the liquid nitrogen reflux pipe 12; the air separation tower 1 is provided with a liquid nitrogen delivery pipe 13, one end of the liquid nitrogen delivery pipe 13 is connected to the liquid nitrogen reflux pipe 12, and the other end of the liquid nitrogen delivery pipe 13 is connected to the top of the upper tower 4.

[0023] Here’s how it works:

[0024] The condenser evaporator 6 mainly exchanges the cold of the liquid oxygen at the bottom of the upper tower 4 to the top of the lower tower 5 for condensing nitrogen to form liquid nitrogen, and the heat of the lower tower 5 is exchanged to the evaporation side of the condenser evaporator 6 for evaporating liquid oxygen to form gaseous oxygen, thereby providing reflux liquid and rising steam for the distillation process.

[0025] 1. First, the air is compressed, purified, and cooled, and then sent to the lower tower 5 through the compressed air delivery pipe 18 as the rising gas of the lower tower 5. The liquid nitrogen condensed on the condensation side of the condenser evaporator 6 flows down from the top of the lower tower 5 as the reflux liquid. After the reflux liquid and the rising gas undergo a heat and mass transfer distillation process on the layers of tower plates or fillers in the lower tower 5, the reflux liquid accumulates at the bottom of the lower tower 5 to obtain oxygen-rich liquid air; the rising gas rises to the top of the lower tower 5 and is condensed into liquid nitrogen on the condensation side of the condenser evaporator 6.

[0026] 2. The oxygen-rich liquid air in the lower tower 5 is introduced into the upper middle part of the upper tower 4 through the liquid air delivery pipe 17 after throttling and pressure reduction, and is used as the raw material for further distillation in the stripping section of the upper tower 4. The distillation principle is the same as that of the lower tower 5. The oxygen-rich liquid air flows downward and the ascending steam undergoes multiple partial evaporations and partial condensations, and then flows downward to the bottom of the upper tower 4 to obtain liquid oxygen.

[0027] 3. The liquid nitrogen at the top of the lower tower 5 is sent to the top of the upper tower 4 through the liquid nitrogen delivery pipe 13 after throttling and reducing the pressure, and is used as the reflux liquid of the distillation section. After multiple partial evaporations, it reaches the top of the upper tower 4, and then gaseous nitrogen can be obtained and discharged through the nitrogen discharge pipe 14. The dirty nitrogen gas formed in multiple evaporations is discharged through the dirty nitrogen discharge pipe 15, the oxygen is discharged through the oxygen discharge pipe 11, the liquid oxygen is discharged through the liquid oxygen extraction pipe 7, and the argon fraction gas is discharged into the crude argon tower through the argon fraction gas discharge pipe 16 for further distillation.

[0028] At the initial stage of liquid accumulation, there is no liquid on the evaporation side of the condenser evaporator 6, and the cold is recovered through the subcooler. The throttling valves on the liquid air delivery pipe 17 and the liquid nitrogen delivery pipe 13 throttle and cool down to slowly produce liquid accumulation at the bottom of the upper tower 4. After the liquid level accumulates to the plate unit that contacts the condenser evaporator 6 (the bottom of the condenser evaporator 6 is still some distance away from the bottom of the lower tower 5, and the liquid will not work if the liquid level does not contact the plate unit of the condenser evaporator 6 at the initial stage of liquid appearance), the heat exchange work begins, and the nitrogen rising in the lower tower 5 can be liquefied into liquid nitrogen to provide reflux liquid for the lower tower 5, and then provide reflux liquid for the upper tower 4. The reflux liquid replenishes the liquid level of the condenser evaporator 6, and the liquid level of the condenser evaporator 6 continues to rise, and its heat exchange area increases. In this way, liquid accumulates continuously until the liquid submerges about 80% of the condenser evaporator 6, and the equipment gradually starts to work to full load with the liquid accumulation process. This liquid accumulation process generally takes more than ten to twenty hours. Liquid nitrogen and air are introduced into the upper tower 4, the liquid nitrogen vaporizes and absorbs heat, and the air is condensed and flows down to the liquid accumulation at the bottom of the upper tower 4. The process of condensation and liquid accumulation still needs to be carried out at the top of the upper tower 4. The process of condensation and liquid accumulation takes a long time, resulting in a slow startup speed.

[0029] After the improvement, a cooling pipe 22 is added, one end of which is connected to the middle and lower part of the upper tower 4 and the other end is connected to the top of the lower tower 5. In the cooling stage, the cooling pipe 22 is used to connect the top of the lower tower 5 with the middle and lower part of the upper tower 4; a throttle valve 25 and a stop valve 23 are sequentially arranged on the cooling pipe 22 from the lower tower 5 to the upper tower 4. The pressure of the lower tower 5 is much greater than that of the upper tower 4. In practice, the pressure of the upper tower 4 is about 40Kpa, and the pressure of the lower tower 5 is about 0.48Mpa. Therefore, after throttling and reducing the pressure through the throttle valve 25, the cooling gas can flow into the bottom of the upper tower 5 for cooling the evaporation side of the condenser evaporator 6. The stop valve 23 is mainly to cut off the cooling pipe 22 after the cooling stage to prevent the upper tower 4 and the lower tower 5 from being damaged by gas cross-talk during normal production.

[0030] A cold charging mechanism 24 is additionally provided, and the cold charging mechanism 24 comprises a cold charging pipe 2 and a cold charging module 8; the outlet of the cold charging pipe 2 is connected to the bottom of the upper tower 4; the cold charging module 8 is connected to the inlet of the cold charging pipe 2, and is used to supply the output liquid of the air separation tower into the cold charging pipe 2 during the liquid accumulation stage; a low-temperature stop valve 3 is provided between the cold charging module 8 and the inlet of the cold charging pipe 2, the inlet of the low-temperature stop valve 3 is detachably connected to the cold charging module 8, and the outlet of the low-temperature stop valve 3 is fixedly connected to the inlet of the cold charging pipe 2; a hose 9 for outputting the output liquid of the air separation tower is connected to the cold charging module 8, and the hose 9 is connected to the inlet of the low-temperature stop valve 3 through a quick connector 10, and the cold charging module 8 is an air separation tower output liquid storage tank or tank truck with a booster device; the output liquid of the air separation tower is liquid nitrogen or liquid oxygen, and can also be liquid argon, among which liquid argon is relatively expensive and is generally not selected; when liquid nitrogen or liquid argon is selected, the temperature is lower, the cold capacity contained is larger, and the filling process is more safe. The air separation tower output liquid is the cryogenic liquid produced by the air separation tower 1. In practice, part of the cryogenic liquid produced by the previous operation of the air separation tower 1 can be stored and charged into the air separation tower 1 at the next startup to achieve the purpose of rapid startup. The cryogenic liquid produced by the air separation tower 1 is easy to obtain, does not need to be purchased separately, and has low cost.

[0031] In practice, a valve 2 21 is provided on the liquid oxygen extraction pipe 7 at the bottom of the upper tower 4, and a liquid oxygen discharge pipe 19 is connected to the liquid oxygen extraction pipe 7 between the valve 2 21 and the upper tower 4, and a valve 1 20 is provided on the liquid oxygen discharge pipe 19, and the outlet of the cold charging pipe 2 is connected to the liquid oxygen discharge pipe 19 between the valve 1 20 and the liquid oxygen extraction pipe 7. When liquid accumulates, the valve 1 20 and the valve 2 21 are closed, and the cold charging module 8 is quickly connected to the low temperature stop valve 3 through the quick connector 10, and the output liquid of the air separation tower is quickly charged into the cold charging pipe 2 through the inlet of the low temperature stop valve 3, and directly charged into the bottom of the upper tower 4 through the cold charging pipe 2 through part of the liquid oxygen discharge pipe 19 and part of the liquid oxygen extraction pipe 7, and the output liquid of the air separation tower quickly forms a liquid level on the evaporation side of the condenser evaporator 6 at the bottom of the upper tower 4 to about 80% of the liquid level during normal operation, and the condenser evaporator 6 can gradually work to full load, which is equivalent to eliminating the process of slowly accumulating liquid on the evaporation side of the condenser evaporator 6, shortening the liquid accumulation time, and reducing the overall operation cost of the air separation tower 1. Connecting the cold filling pipe 2 with the bottom of the upper tower 4 through the liquid oxygen discharge pipe 19 and the liquid oxygen extraction pipe 7 is equivalent to utilizing the existing pipelines. During implementation, there is no need for cold box sand removal and high-altitude operations, which can effectively reduce costs. The outlet of the cold filling pipe 2 can also be directly connected to the bottom of the upper tower 4, but this requires the addition of a very long pipeline, and the cost will rise sharply.

[0032] This solution uses the cold charging module 8 to pass the air separation tower output liquid (which can be liquid nitrogen or liquid oxygen) to the bottom of the upper tower 4 to directly submerge the evaporation side of the condenser evaporator 6 to about 80%, and replaces the liquid accumulation process with the air separation tower output liquid. It only takes one to two hours, which greatly shortens the liquid accumulation time compared to before the improvement, realizes rapid startup and rapid production, reduces power consumption, and greatly improves the overall efficiency of the system.

[0033] Taking the KDON21000 / 22000 air separation equipment of Laiwu Tianyuan Gas Co., Ltd. as an example, the purpose of heating and purging during hot start-up is to blow away impurities and free water in the tower and pipeline until the dew point is qualified, and then the expander is turned on to cool the entire device, cooling the air separation equipment from room temperature to a temperature close to the air liquefaction temperature, and then turning it into the liquid accumulation stage. Liquid air begins to appear at the bottom of the lower tower 5, and the liquid air and wet steam are further cooled by the throttle valve and accumulate on the evaporation side of the condenser evaporator 6. As the liquid level of the condenser evaporator 6 accumulates, it starts to work, and the air of the air compressor gradually eats into the lower tower 5. After the liquid level of the condenser evaporator 6 reaches the specified range, the liquid accumulation ends, and the purity is adjusted later. At the beginning of the liquid accumulation, the liquid of the condenser evaporator 6 needs to be discharged several times, mainly to prevent the accumulation of hydrocarbons in the condenser evaporator 6 from causing danger. This liquid accumulation stage takes about 25 hours, while through this solution, it only takes about 3 hours for the condenser evaporator to reach the normal liquid level of 3700mm, and the time shortening effect is significant.

[0034] Charging the output liquid of the air separation tower into the condenser evaporator 6 can quickly establish the liquid level of the condenser evaporator 6, greatly reducing the time spent in the liquid accumulation stage. The pressure of the upper tower 4 is about 40kpa, and the height from the cold filling port (the inlet of the low-temperature stop valve 3) to the condenser evaporator 6 is about 25 meters. In practice, the pressure required for charging can be calculated according to the density of the liquid nitrogen or liquid oxygen charged. After liquid appears in the condenser evaporator 6 and is drained several times, the tower is now completely cold, preventing large stress from being generated during charging, causing leakage of the pipeline or the condenser evaporator 6; when charging, the charging speed is controlled according to the monitored tower pressure, resistance and other measuring point values ​​to prevent the lower tower 5 from suddenly taking in a large amount of air, causing the air compressor to shut down due to low pressure interlock.

[0035] Obviously, the above embodiments of the utility model are only examples for clearly explaining the technical solution of the utility model, and are not intended to limit the specific implementation methods of the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the claims of the utility model shall be included in the protection scope of the claims of the utility model.

Claims

1. An air separation device, characterized in that: The invention comprises an air separation tower (1), a cold charging pipe (2) and a cold charging module (8); the air separation tower (1) comprises an upper tower (4) and a lower tower (5) which are connected in sequence, a condenser evaporator (6) is arranged between the upper tower (4) and the lower tower (5), the evaporation side of the condenser evaporator (6) is arranged at the bottom of the upper tower (4), and the condensation side of the condenser evaporator (6) is arranged at the top of the lower tower (5); The outlet of the cold charging pipe (2) is connected to the bottom of the upper tower (4); The cold charging module (8) is connected to the inlet of the cold charging pipe (2) and is used to supply the air separation tower output liquid into the cold charging pipe (2) during the liquid accumulation stage.

2. An air separation device according to claim 1, characterized in that: A low-temperature stop valve (3) is provided between the cold charging module (8) and the inlet of the cold charging pipe (2); the inlet of the low-temperature stop valve (3) is detachably connected to the cold charging module (8), and the outlet of the low-temperature stop valve (3) is fixedly connected to the inlet of the cold charging pipe (2).

3. An air separation device according to claim 2, characterized in that: The cold charging module (8) is connected to a hose (9) for outputting the output liquid of the air separation tower, and the hose (9) is connected to the inlet of the low-temperature stop valve (3) through a quick connector (10).

4. An air separation device according to claim 1, characterized in that: The cold charging module (8) is an air separation tower output liquid storage tank or tank truck with a pressurizing device.

5. An air separation device according to claim 1, characterized in that: The output liquid of the air separation tower is liquid nitrogen or liquid oxygen.

6. An air separation device according to claim 1, characterized in that: A liquid oxygen extraction pipe (7) is provided at the bottom of the upper tower (4), a second valve (21) is provided on the liquid oxygen extraction pipe (7), a liquid oxygen discharge pipe (19) is connected to the liquid oxygen extraction pipe (7) between the second valve (21) and the upper tower (4), a first valve (20) is provided on the liquid oxygen discharge pipe (19), and an outlet of the cold charging pipe (2) is connected to the liquid oxygen discharge pipe (19) between the first valve (20) and the liquid oxygen extraction pipe (7).

7. An air separation device according to claim 6, characterized in that: A nitrogen discharge pipe (14), a dirty nitrogen discharge pipe (15), an argon fraction gas discharge pipe (16) and an oxygen discharge pipe (11) are sequentially arranged from the top of the upper tower (4) downward, and the oxygen discharge pipe (11) is located higher than the liquid oxygen extraction pipe (7).

8. An air separation device according to claim 1, characterized in that: The lower tower (5) is provided with a liquid nitrogen reflux pipe (12), the liquid nitrogen reflux pipe (12) having a first end and a second end, the first end of the liquid nitrogen reflux pipe (12) being used to connect to a liquid nitrogen receiving tank provided at the top of the lower tower (5), the second end of the liquid nitrogen reflux pipe (12) being connected to the top of the lower tower (5), the height of the second end of the liquid nitrogen reflux pipe (12) being smaller than the height of the first end of the liquid nitrogen reflux pipe (12), and a valve being provided on the liquid nitrogen reflux pipe (12).

9. An air separation device according to claim 8, characterized in that: The air separation tower (1) is provided with a liquid nitrogen delivery pipe (13), one end of the liquid nitrogen delivery pipe (13) is connected to the liquid nitrogen reflux pipe (12), and the other end of the liquid nitrogen delivery pipe (13) is connected to the top of the upper tower (4).

10. An air separation device according to any one of claims 1 to 9, characterized in that: The air separation tower (1) is provided with a liquid air delivery pipe (17), the bottom of the lower tower (5) is connected to the upper middle part of the upper tower (4) through the liquid air delivery pipe (17), and the lower middle part of the lower tower (5) is connected to a compressed air delivery pipe (18).

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