Liquefaction storage device for air separation gaseous product

Abstract

The utility model relates to a liquefaction storage device for air separation gaseous products, which comprises a nitrogen conveying header pipe and a liquid nitrogen storage tank. A first nitrogen compressor, a first reflux nitrogen delivery pipe, a second nitrogen compressor, a first pressure nitrogen shunt pipe, a first turbo expander, a second turbo expander, a second pressure nitrogen shunt pipe and a first throttle valve are arranged on the nitrogen delivery header pipe, and the first pressure nitrogen shunt pipe is communicated with the second turbo expander; the second pressure nitrogen flow dividing pipe is communicated with the first turbo expander, a main heat exchanger is arranged on the nitrogen conveying header pipe, the first backflow nitrogen conveying pipe, the first pressure nitrogen flow dividing pipe and the second pressure nitrogen flow dividing pipe, a first liquid nitrogen conveying pipe and a second liquid nitrogen conveying pipe are arranged on the first throttling valve, the first liquid nitrogen conveying pipe is communicated with a liquid nitrogen storage tank, and the second liquid nitrogen conveying pipe is communicated with a second turbo expander. And a nitrogen liquefier is arranged on the second liquid nitrogen conveying pipe and the liquid nitrogen storage tank. And gaseous products released by the low-temperature rectification system due to excess capacity are recovered. 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 liquefied storage equipment of air separation gaseous product, concretely relates to a liquefied storage device of air separation gaseous product. BACKGROUND

[0002] The low-temperature rectification method is also called cryogenic separation method, and the principle of the cryogenic method air separation is to use air as raw material, compress, purify, and use heat exchange to liquefy air into liquid air. The liquid air is mainly a mixture of liquid oxygen and liquid nitrogen, and nitrogen and oxygen are obtained by using the different boiling points of liquid oxygen and liquid nitrogen to separate them through rectification. Specifically, the raw air is filtered by a self-cleaning filter to remove dust and mechanical impurities, and then enters a main air compressor. The compressed gas is cooled by an air pre-cooling device and then sent to a purification device to remove impurities such as water and carbon dioxide to form adsorbed compressed air. The adsorbed compressed air is exchanged with other gas media through a main heat exchanger and then sent to a rectification tower as raw material for low-temperature rectification. The ordinary nitrogen-oxygen separation rectification tower includes an upper tower, a main condensing heat exchanger and a lower tower from top to bottom. After the raw material is sent to the rectification tower for rectification, the finished nitrogen and oxygen are produced outwardly in the upper tower, and the main condensing heat exchanger produces finished liquid oxygen and liquid nitrogen. The upper tower uses the oxygen-rich liquid air transported from the lower tower to the upper tower, and uses the oxygen-rich liquid air entering the upper tower to exchange heat with the gas evaporated from the main condensing evaporator and the liquid nitrogen returned to the upper tower, and then produces finished nitrogen, oxygen and liquid oxygen.

[0003] The air separation product obtained by using the low-temperature rectification method has a higher proportion of gaseous air separation product. When the downstream user has a high demand for gaseous air separation product and the output efficiency of the low-temperature rectification device is insufficient to meet the demand, the liquid product can be vaporized and supplemented to the gaseous air separation product for delivery to the downstream user to meet the demand of the customer for the product. However, when the load of the downstream user decreases and the demand for gaseous air separation product of the low-temperature rectification device decreases, the adjustment of the load of the low-temperature rectification system often lags behind the demand of the downstream user. During the adjustment of the low-temperature rectification system from high load to low load, a large amount of excess gaseous air separation product will be produced. In the prior art, the excess gaseous air separation product is directly discharged and treated for consideration of the finished product. However, since the discharged gaseous air separation product has already paid the energy cost in the process of low-temperature rectification, the discharge of the excess gaseous air separation product by the low-temperature rectification system not only causes waste of product but also causes waste of energy. Therefore, the prior art has room for improvement, so that the excess gaseous air separation product produced by the low-temperature rectification system due to excess capacity can be recovered when the load of the downstream user decreases and the demand for gaseous air separation product decreases, to meet the market demand. SUMMARY

[0004] The utility model provides a liquefied storage device of air separation gaseous product which can provide cold energy to recover gaseous product released by low-temperature rectification system due to overcapacity, and overcomes the defects in the prior art.

[0005] The technical scheme of the utility model adopts: a liquefied storage device of air separation gaseous product, including nitrogen gas delivery main pipe and liquid nitrogen storage tank, nitrogen gas delivery main pipe's import end to nitrogen gas delivery main pipe's export end direction along the first nitrogen compressor, first reflux nitrogen gas delivery pipe's export end, second nitrogen compressor, first pressure nitrogen gas shunt pipe's import end, first turbine expander's pressure increasing end, second turbine expander's pressure increasing end, second pressure nitrogen gas shunt pipe's import end and first throttle valve's import end are sequentially provided with, first pressure nitrogen gas shunt pipe's export end and second turbine expander's expansion end import are linked together, second pressure nitrogen gas shunt pipe's export end and first turbine expander's expansion end import are linked together, and second turbine expander's expansion end export and first turbine expander's expansion end export all are linked together with first reflux nitrogen gas delivery pipe, and nitrogen gas delivery main pipe, first reflux nitrogen gas delivery pipe, first pressure nitrogen gas shunt pipe and second pressure nitrogen gas shunt pipe are provided with main heat exchanger, and first liquid nitrogen delivery pipe and second liquid nitrogen delivery pipe are provided on first throttle valve's export end, first liquid nitrogen delivery pipe and liquid nitrogen storage tank are linked together, and the cold source channel of nitrogen liquefier is provided on second liquid nitrogen delivery pipe, and the heat source channel of nitrogen liquefier is provided with nitrogen liquefaction pipe, the import end of nitrogen liquefaction pipe and the top of liquid nitrogen storage tank are linked together, and the export end of nitrogen liquefaction pipe and the bottom of liquid nitrogen storage tank are linked together.

[0006] Preferably, the nitrogen gas delivery main pipe between the pressure increasing end of the second turbine expander and the first throttle valve is installed on the main heat exchanger, and the nitrogen gas delivery main pipes between the first nitrogen compressor and the first reflux nitrogen gas delivery pipe, between the second nitrogen compressor and the first pressure nitrogen gas shunt pipe, and between the pressure increasing end of the second turbine expander and the main heat exchanger are respectively provided with after-heat exchangers.

[0007] Preferably, the import end of a third liquid nitrogen delivery pipe is further provided on the export end of the first throttle valve, and a subcooler is provided on the first liquid nitrogen delivery pipe and the third liquid nitrogen delivery pipe, a liquid oxygen delivery branch pipe is provided on the subcooler, and a liquid oxygen storage tank is provided on the export end of the liquid oxygen delivery branch pipe.

[0008] Preferably, the main heat exchanger is provided with an oxygen liquefied delivery pipe, the outlet end of the oxygen liquefied delivery pipe is communicated with a liquid oxygen storage tank, a first regulating valve is arranged on the oxygen liquefied delivery pipe between the liquid oxygen storage tank and the main heat exchanger, an oxygen delivery branch pipe is communicated with the oxygen liquefied delivery pipe between the liquid oxygen storage tank and the first regulating valve, a second regulating valve is arranged on the oxygen delivery branch pipe between the liquid oxygen storage tank and the subcooler, a first temperature sensor is arranged on the oxygen delivery branch pipe between the liquid oxygen storage tank and the second regulating valve, the liquid oxygen storage tank is provided with a liquid oxygen product delivery pipe, and a liquid oxygen delivery pump and a second temperature sensor are arranged on the liquid oxygen product delivery pipe.

[0009] Preferably, the outlet end of the third liquid nitrogen delivery pipe, the outlet end of the second liquid nitrogen delivery pipe and the main heat exchanger are provided with a second backflow nitrogen delivery pipe, the inlet end of the nitrogen delivery main pipe is communicated with the outlet end of the second backflow nitrogen delivery pipe between the first nitrogen compressor, the outlet end of the first throttle valve is further provided with the inlet end of the fourth liquid nitrogen delivery pipe, and the second backflow nitrogen delivery pipe between the main heat exchanger and the nitrogen delivery main pipe is communicated with the outlet end of the fourth liquid nitrogen delivery pipe.

[0010] Preferably, the fourth liquid nitrogen delivery pipe between the first throttle valve and the main heat exchanger, the third liquid nitrogen delivery pipe between the first throttle valve and the subcooler and the second liquid nitrogen delivery pipe between the first throttle valve and the nitrogen liquefier are respectively provided with second throttle valves, the first pressure nitrogen shunt pipe between the main heat exchanger and the expansion end of the second turbine expander, the second pressure nitrogen shunt pipe and the first liquid nitrogen delivery pipe between the subcooler and the liquid nitrogen storage tank are respectively provided with third regulating valves, and the first liquid nitrogen delivery pipe between the subcooler and the liquid nitrogen storage tank is provided with a third temperature sensor.

[0011] Preferably, the nitrogen liquefaction pipe between the nitrogen liquefier and the liquid nitrogen storage tank is sequentially provided with a fourth temperature sensor and a liquid nitrogen booster pump in the direction from the nitrogen liquefier to the liquid nitrogen storage tank, and the nitrogen liquefaction pipe between the liquid nitrogen booster pump and the liquid nitrogen storage tank is communicated with the outlet end of the first liquid nitrogen delivery pipe.

[0012] The utility model has the advantages that: firstly, the utility model utilizes the finished product nitrogen gas produced by the low-temperature rectification system to provide the conditions for the finished product nitrogen gas and the finished product oxygen gas to be liquefied and stored, and utilizes the second refrigeration cycle to provide the cold source for the liquefied oxygen gas and the subcooled liquefied oxygen gas and the cold source for the nitrogen gas evaporated from the liquid nitrogen storage tank to be liquefied again; when the downstream user load is low, the low-temperature rectification system is still in the state of transforming from high load to low load, and the excess finished product nitrogen gas and the finished product oxygen gas produced by the low-temperature rectification system can be changed from gaseous state to liquid state to form liquid oxygen and liquid nitrogen as liquid products, thereby reducing the waste caused by the finished product oxygen gas and the finished product nitrogen gas being exhausted as gaseous products.

[0013] Secondly, the utility model liquid oxygen storage tank is provided with a pressure relief valve and a liquid level sensor. Installing the pressure relief valve on the liquid oxygen storage tank is convenient for balancing the pressure in the liquid oxygen storage tank, and installing the liquid level sensor on the liquid oxygen storage tank is convenient for feeding back the liquid level height in the liquid oxygen storage tank.

[0014] The utility model has the advantages of simple structure, convenient operation, ingenious design, greatly improved work efficiency, good social and economic benefits, and is a product that is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the present utility model.

[0016] Figure 2 for Figure 1 A partially enlarged schematic diagram of detail A. DETAILED DESCRIPTION

[0017] like Figure 1 and Figure 2 As shown, a liquefied storage device for air separation gaseous products includes a nitrogen delivery main pipe 1 and a liquid nitrogen storage tank 2. The nitrogen delivery main pipe 1 is sequentially provided with a first nitrogen compressor 3, an outlet end of a first reflux nitrogen delivery pipe 4, a second nitrogen compressor 5, an inlet end of a first pressure nitrogen diverter pipe 6, a boosting end of a first turbine expander 7, a boosting end of a second turbine expander 8, an inlet end of a second pressure nitrogen diverter pipe 9 and an inlet end of a first throttle valve 10 along the direction from the inlet end of the nitrogen delivery main pipe 1 to the outlet end of the nitrogen delivery main pipe 1. The first nitrogen compressor 3 and the second nitrogen compressor 5 both adopt centrifugal compressors. The outlet end of the first pressure nitrogen diverter pipe 6 is connected to the inlet end of the expansion end of the second turbine expander 8. The outlet end of the second pressure nitrogen diverter pipe 9 is connected to the expansion end of the first turbine expander 7. The inlet of the second turboexpander 8 and the outlet of the expansion end of the first turboexpander 7 are both connected to the first reflux nitrogen delivery pipe 4. A main heat exchanger 11 is provided on the nitrogen delivery main pipe 1, the first reflux nitrogen delivery pipe 4, the first pressure nitrogen diversion pipe 6 and the second pressure nitrogen diversion pipe 9. A first liquid nitrogen delivery pipe 12 and a second liquid nitrogen delivery pipe 13 are provided on the outlet end of the first throttle valve 10. The first liquid nitrogen delivery pipe 12 is connected to the liquid nitrogen storage tank 2. A cold source channel of a nitrogen liquefier 14 is provided on the second liquid nitrogen delivery pipe 13. A nitrogen liquefaction pipe 15 is provided on the heat source channel of the nitrogen liquefier 14. The inlet end of the nitrogen liquefaction pipe 15 is connected to the top of the liquid nitrogen storage tank 2, and the outlet end of the nitrogen liquefaction pipe 15 is connected to the bottom of the liquid nitrogen storage tank 2. The inlet end of the first reflux nitrogen gas delivery pipe 4 is connected to the expansion end outlet of the first turbine expander 7 , and the expansion end outlet of the second turbine expander 8 is connected to the first reflux nitrogen gas delivery pipe 4 via the third pressure nitrogen diversion pipe 16 .

[0018] The nitrogen delivery main pipe 1 between the pressurized end of the second turbo-expander 8 and the first throttle valve 10 is installed on the main heat exchanger 11, the nitrogen delivery main pipe 1 between the first nitrogen compressor 3 and the first backflow nitrogen delivery pipe 4, the nitrogen delivery main pipe 1 between the second nitrogen compressor 5 and the first pressure nitrogen branch pipe 6, and the nitrogen delivery main pipe 1 between the pressurized end of the second turbo-expander 8 and the main heat exchanger 11 are respectively provided with a machine after heat exchanger 17. The installation of the machine after heat exchanger 17 facilitates the absorption of the heat rise caused by the compression of nitrogen, and the heat source channel of the compressed nitrogen into the machine after heat exchanger 17 and the cold source continuously delivered to the cold source channel of the machine after heat exchanger 17 are used for counterflow heat exchange, so as to realize the reduction of the temperature of the compressed nitrogen.

[0019] The outlet end of the first throttle valve 10 is further provided with the inlet end of the third liquid nitrogen delivery pipe 18, the first liquid nitrogen delivery pipe 12 and the third liquid nitrogen delivery pipe 18 are provided with a subcooler 19, the subcooler 19 is provided with a liquid oxygen delivery branch pipe 20, and the outlet end of the liquid oxygen delivery branch pipe 20 is provided with a liquid oxygen storage tank 21. The liquid oxygen storage tank 21 is provided with a pressure relief valve 39 and a liquid level sensor 36. The installation of the pressure relief valve 39 on the liquid oxygen storage tank 21 facilitates the balance of the pressure in the liquid oxygen storage tank 21, and the installation of the liquid level sensor 36 on the liquid oxygen storage tank 21 facilitates the feedback of the liquid level height in the liquid oxygen storage tank 21.

[0020] The main heat exchanger 11 is provided with an oxygen liquefaction delivery pipe 22, the outlet end of the oxygen liquefaction delivery pipe 22 is connected with the liquid oxygen storage tank 21, the oxygen liquefaction delivery pipe 22 between the liquid oxygen storage tank 21 and the main heat exchanger 11 is provided with a first regulating valve 23, the oxygen liquefaction delivery pipe 22 between the liquid oxygen storage tank 21 and the first regulating valve 23 is connected with the liquid oxygen delivery branch pipe 20, and the liquid oxygen delivery branch pipe 20 between the subcooler 19 and the liquid oxygen storage tank 21 is provided with a second regulating valve 24, so that the liquid oxygen discharged from the low temperature end of the main heat exchanger 11 is divided into two parts, the first part of the liquid oxygen is delivered through the liquid oxygen delivery branch pipe 20, and the heat source channel of the liquid oxygen delivered into the subcooler 19 is subcooled by the cold source continuously delivered into the subcooler 19 and then delivered into the liquid oxygen storage tank 21, and the other part continues to move along the oxygen liquefaction delivery pipe 22 and is delivered into the liquid oxygen storage tank 21; and then it is convenient to adjust the subcooling degree of the liquid oxygen product delivered into the liquid oxygen storage tank 21. The liquid oxygen delivery branch pipe 20 between the liquid oxygen delivery branch pipe 20 and the liquid oxygen storage tank 21 is provided with a first temperature sensor 25, the liquid oxygen storage tank 21 is provided with a liquid oxygen product delivery pipe 26, the liquid oxygen product delivery pipe 26 is provided with a liquid oxygen delivery pump 27 and a second temperature sensor 28. The installation of the second temperature sensor 28 facilitates the feedback of the temperature parameter of the delivery medium through the liquid oxygen product delivery pipe 26.

[0021] The outlet end of the third liquid nitrogen delivery pipe 18, the outlet end of the second liquid nitrogen delivery pipe 13 and the main heat exchanger 11 are provided with a second backflow nitrogen gas delivery pipe 29. The nitrogen gas delivery main pipe 1 between the inlet end of the nitrogen gas delivery main pipe 1 and the first nitrogen compressor 3 is connected to the outlet end of the second backflow nitrogen gas delivery pipe 29. The outlet end of the first throttle valve 10 is further provided with the inlet end of a fourth liquid nitrogen delivery pipe 30. The second backflow nitrogen gas delivery pipe 29 between the main heat exchanger 11 and the nitrogen gas delivery main pipe 1 is connected to the outlet end of the fourth liquid nitrogen delivery pipe 30. The nitrogen gas delivery main pipe 1 between the inlet end of the nitrogen gas delivery main pipe 1 and the second backflow nitrogen gas delivery pipe 29 is provided with a gas flow sensor 37. The gas flow sensor 37 is installed to facilitate feedback of the flow of finished nitrogen gas received by the inlet end of the nitrogen gas delivery main pipe 1. The fourth liquid nitrogen delivery pipe 30 between the first throttle valve 10 and the main heat exchanger 11, the third liquid nitrogen delivery pipe 18 between the first throttle valve 10 and the supercooler 19 and the second liquid nitrogen delivery pipe 13 between the first throttle valve 10 and the nitrogen gas liquefier 14 are respectively provided with a second throttle valve 31. The first pressure nitrogen gas shunt pipe 6 between the main heat exchanger 11 and the expansion end of the second turbo expander 8, the second pressure nitrogen gas shunt pipe 9 and the first liquid nitrogen delivery pipe 12 between the supercooler 19 and the liquid nitrogen storage tank 2 are respectively provided with a third regulating valve 32. The first liquid nitrogen delivery pipe 12 between the supercooler 19 and the liquid nitrogen storage tank 2 is provided with a third temperature sensor 33.

[0022] The nitrogen gas liquefaction pipe 15 between the nitrogen gas liquefier 14 and the liquid nitrogen storage tank 2 is sequentially provided with a fourth temperature sensor 34 and a liquid nitrogen booster pump 35 along the direction from the nitrogen gas liquefier 14 to the liquid nitrogen storage tank 2. The nitrogen gas liquefaction pipe 15 between the liquid nitrogen booster pump 35 and the liquid nitrogen storage tank 2 is connected to the outlet end of the first liquid nitrogen delivery pipe 12. The nitrogen gas liquefaction pipe 15 between the first liquid nitrogen delivery pipe 12 and the liquid nitrogen storage tank 2 is provided with a liquid flow sensor 38.

[0023] The use method of the product is as follows, as shown in Figure 1 and Figure 2 , comprising the following steps:

[0024] S1, the upstream finished nitrogen gas is delivered to the nitrogen gas delivery main pipe 1. The finished nitrogen gas travels along the nitrogen gas delivery main pipe 1 and is compressed by the first nitrogen compressor 3 and the second nitrogen compressor 5 in turn, and is then divided into two parts, i.e. the first part of the pressurized nitrogen gas and the second part of the pressurized nitrogen gas.

[0025] The first part of the pressurized nitrogen gas is delivered to the first pressure nitrogen gas shunt pipe 6, enters the first heat source channel of the main heat exchanger 11 and is continuously delivered to the cold source of the main heat exchanger 11, and then is discharged from the high temperature zone of the main heat exchanger 11, is sent to the expansion end of the second turbo expander 8 for expansion and cooling, and then is sent to the first backflow nitrogen gas delivery pipe 4 through the medium temperature zone of the main heat exchanger 11.

[0026] The second part of the pressurized nitrogen continues to move along the nitrogen delivery main pipe 1, and then is pressurized by the pressurized end of the first turbo expander 7 and the pressurized end of the second turbo expander 8, and is then sent from the high-temperature end of the second heat source channel of the main heat exchanger 11 into the second heat source channel of the main heat exchanger 11 and continues to exchange heat with the cold source of the main heat exchanger 11. When the second part of the pressurized nitrogen reaches the medium-temperature zone of the main heat exchanger 11, it is again divided into two parts, i.e., a third part of the pressurized nitrogen and a fourth part of the pressurized nitrogen.

[0027] The third part of the pressurized nitrogen is discharged from the medium-temperature zone of the main heat exchanger 11, and then is sent into the expansion end of the first turbo expander 7 through the second pressure nitrogen shunt pipe 9, and is then sent into the first return flow nitrogen delivery pipe 4 after being expanded and cooled. Then, the third part of the pressurized nitrogen moves along the first return flow nitrogen delivery pipe 4, enters the first cold source channel of the main heat exchanger 11 through the low-temperature end of the main heat exchanger 11, and is then sent into the heat source of the main heat exchanger 11. When the third part of the pressurized nitrogen reaches the medium-temperature zone of the main heat exchanger 11, it is combined with the first part of the pressurized nitrogen that is sent into the first return flow nitrogen delivery pipe 4 through the expansion end of the second turbo expander 8 to form a fifth part of the pressurized nitrogen, and the fifth part of the pressurized nitrogen continues to move along the high-temperature end of the first cold source channel of the main heat exchanger 11. The fifth part of the pressurized nitrogen is discharged from the high-temperature end of the first cold source channel of the main heat exchanger 11, and then continues to move along the first return flow nitrogen delivery pipe 4 to be combined with the finished product nitrogen that is compressed by the second nitrogen compressor 5 to form the first circulating cooling.

[0028] The fourth part of the pressurized nitrogen continues to move towards the low-temperature end of the second heat source channel of the main heat exchanger 11. When the fourth part of the pressurized nitrogen is discharged from the low-temperature end of the second heat source channel of the main heat exchanger 11, it forms liquid nitrogen, and then continues to move along the nitrogen delivery main pipe 1 and is continuously sent to the first throttling valve 10.

[0029] S2, the liquid nitrogen delivered from the outlet end of the first throttling valve 10 is divided into four parts, i.e., a first part of the liquid nitrogen, a second part of the liquid nitrogen, a third part of the liquid nitrogen, and a fourth part of the liquid nitrogen. The first part of the liquid nitrogen is sent into the main heat exchanger 11 from the low-temperature end of the second cold source channel of the main heat exchanger 11 through the fourth liquid nitrogen delivery pipe 30, and continues to exchange heat with the heat source of the main heat exchanger 11. The first part of the liquid nitrogen is discharged from the high-temperature end of the second cold source channel of the main heat exchanger 11 to form the first vaporized nitrogen gas, and then continues to be delivered into the second return flow nitrogen delivery pipe 29 through the outlet end of the fourth liquid nitrogen delivery pipe 30.

[0030] The second part of liquid nitrogen enters the third liquid nitrogen delivery pipe 18 and is throttled by the second throttle valve 31 on the third liquid nitrogen delivery pipe 18 and then delivered to the low-temperature end of the cold source channel of the subcooler 19 and continuously delivered to the heat source of the subcooler 19 for heat exchange. The second part of liquid nitrogen continues to move toward the high-temperature end of the cold source channel of the subcooler 19. When the second part of liquid nitrogen continues to be discharged toward the high-temperature end of the cold source channel of the subcooler 19, it forms a second vaporized nitrogen and is delivered to the second reflux nitrogen delivery pipe 29.

[0031] The third portion of liquid nitrogen enters the second liquid nitrogen delivery pipe 13, is throttled by the second throttle valve 31 on the second liquid nitrogen delivery pipe 13, and is then delivered to the cold source channel of the nitrogen liquefier 14 for heat exchange with the heat source continuously delivered to the nitrogen liquefier 14. The third portion of liquid nitrogen is discharged from the high-temperature end of the cold source channel of the nitrogen liquefier 14 to form a third vaporized nitrogen.

[0032] The fourth portion of liquid nitrogen is transported to the first heat source channel of the subcooler 19 through the first liquid nitrogen delivery pipe 12 and continuously delivered to the cold source of the subcooler 19 for heat exchange to form subcooled liquid nitrogen, and then continues to move along the first liquid nitrogen delivery pipe 12 and is finally delivered to the liquid nitrogen storage tank 2.

[0033] The second vaporized nitrogen and the third vaporized nitrogen entering the second reflux nitrogen delivery pipe 29 are combined to form the fifth vaporized nitrogen, which is delivered to the third cold source channel of the main heat exchanger 11 and the heat source continuously supplied to the main heat exchanger 11. After heat exchange, the fifth vaporized nitrogen is discharged from the high-temperature end of the main heat exchanger 11 and combined with the first vaporized nitrogen to form the sixth vaporized nitrogen. The sixth vaporized nitrogen continues to move along the second reflux nitrogen delivery pipe 29 and is delivered to the nitrogen delivery main pipe 1 and combined with the finished nitrogen that has not been compressed by the first nitrogen compressor 3 to form the second refrigeration cycle.

[0034] S3, the seventh vaporized nitrogen formed by the vaporization of the liquid nitrogen temporarily stored in the liquid nitrogen storage tank 2 is transported to the heat source channel of the nitrogen liquefier 14 through the nitrogen liquefaction pipe 15 and exchanges heat with the cold source continuously supplied to the nitrogen liquefier 14, where it is liquefied again to form the fifth portion of liquid nitrogen, which is then discharged from the nitrogen liquefier 14 and continues to move along the nitrogen liquefaction pipe 15, is pressurized by the liquid nitrogen booster pump 35, and is then transported back to the liquid nitrogen storage tank 2.

[0035] The finished product oxygen of the upstream delivery is delivered to the oxygen liquefaction delivery pipe 22, and then passes through the third heat source channel of the main heat exchanger 11 and continuously exchanges heat with the cold source of the main heat exchanger 11. When the finished product oxygen is discharged from the low-temperature end of the third heat source channel of the main heat exchanger 11, liquid oxygen is formed and divided into two parts, i.e., a first part of liquid oxygen and a second part of liquid oxygen. The first part of liquid oxygen continues to move along the oxygen liquefaction delivery pipe 22 and is delivered to the liquid oxygen storage tank 21. The second part of liquid oxygen is delivered to the first heat source channel of the supercooler 19 through the liquid oxygen delivery branch pipe 20 and continuously exchanges heat with the cold source of the supercooler 19 to form supercooled liquid oxygen, which continues to move along the liquid oxygen delivery branch pipe 20 and is delivered to the liquid oxygen storage tank 21.

[0036] Through the embodiment, the first refrigeration cycle is performed by using the finished product nitrogen produced by the low-temperature rectification system, so that the conditions for liquefying and storing the finished product nitrogen and the finished product oxygen are provided, and the second refrigeration cycle is used to provide the cold source for liquefying the finished product oxygen and supercooling the liquefied finished product oxygen and to provide the cold source for re-liquefying the nitrogen gas evaporated from the liquid nitrogen storage tank 2. When the downstream user load is low, the low-temperature rectification system is still in the state of conversion from high load to low load, and the excess finished product nitrogen and the finished product oxygen produced by the low-temperature rectification system can be changed from gaseous state to liquid state to form liquid oxygen and liquid nitrogen as liquid products, thereby reducing the waste caused by emptying the finished product oxygen and the finished product nitrogen as gaseous products.

[0037] The above-described embodiments are only preferred embodiments of the present application, and are not intended to limit the scope of the present application. Any equivalent changes or modifications made in accordance with the structure, features and principles of the present application should be included in the scope of the present application.

Claims

1. A device for liquefied storage of air-separated gaseous products, comprising a nitrogen delivery header (1) and a liquid nitrogen storage tank (2), characterized in that: The nitrogen delivery main pipe (1) is sequentially provided with a first nitrogen compressor (3), an outlet end of a first backflow nitrogen delivery pipe (4), a second nitrogen compressor (5), an inlet end of a first pressure nitrogen shunt pipe (6), a pressurizing end of a first turbine expander (7), a pressurizing end of a second turbine expander (8), an inlet end of a second pressure nitrogen shunt pipe (9), and an inlet end of a first throttling valve (10) along the direction from the inlet end of the nitrogen delivery main pipe (1) to the outlet end of the nitrogen delivery main pipe (1), the outlet end of the first pressure nitrogen shunt pipe (6) and the expansion end inlet of the second turbine expander (8) are in communication, the outlet end of the second pressure nitrogen shunt pipe (9) and the expansion end inlet of the first turbine expander (7) are in communication, the expansion end outlet of the second turbine expander (8) and the expansion end outlet of the first turbine expander (7) are both in communication with the first backflow nitrogen delivery pipe (4), the main heat exchanger (11) is arranged on the nitrogen delivery main pipe (1), the first backflow nitrogen delivery pipe (4), the first pressure nitrogen shunt pipe (6), and the second pressure nitrogen shunt pipe (9), the first liquid nitrogen delivery pipe (12) and the second liquid nitrogen delivery pipe (13) are arranged on the outlet end of the first throttling valve (10), the first liquid nitrogen delivery pipe (12) and the liquid nitrogen storage tank (2) are in communication, the cold source channel of the nitrogen liquefier (14) is arranged on the second liquid nitrogen delivery pipe (13), the heat source channel of the nitrogen liquefier (14) is arranged with the nitrogen liquefaction pipe (15), the inlet end of the nitrogen liquefaction pipe (15) and the top of the liquid nitrogen storage tank (2) are in communication, and the outlet end of the nitrogen liquefaction pipe (15) and the bottom of the liquid nitrogen storage tank (2) are in communication.

2. The apparatus of claim 1, wherein: The nitrogen delivery main pipe (1) between the pressurizing end of the second turbine expander (8) and the first throttling valve (10) is arranged on the main heat exchanger (11), the nitrogen delivery main pipe (1) between the first nitrogen compressor (3) and the first backflow nitrogen delivery pipe (4), the nitrogen delivery main pipe (1) between the second nitrogen compressor (5) and the first pressure nitrogen shunt pipe (6), and the nitrogen delivery main pipe (1) between the pressurizing end of the second turbine expander (8) and the main heat exchanger (11) are respectively arranged with the post-machine heat exchanger (17).

3. The apparatus of claim 1, wherein: The inlet end of the third liquid nitrogen delivery pipe (18) is further arranged on the outlet end of the first throttling valve (10), the subcooler (19) is arranged on the first liquid nitrogen delivery pipe (12) and the third liquid nitrogen delivery pipe (18), the liquid oxygen delivery branch pipe (20) is arranged on the subcooler (19), and the liquid oxygen storage tank (21) is arranged on the outlet end of the liquid oxygen delivery branch pipe (20).

4. The apparatus of claim 3, wherein: The main heat exchanger (11) is provided with an oxygen liquefaction delivery pipe (22), the outlet end of the oxygen liquefaction delivery pipe (22) is communicated with a liquid oxygen storage tank (21), a first regulating valve (23) is arranged on the oxygen liquefaction delivery pipe (22) between the liquid oxygen storage tank (21) and the main heat exchanger (11), the oxygen liquefaction delivery pipe (22) between the liquid oxygen storage tank (21) and the first regulating valve (23) is communicated with a liquid oxygen delivery branch pipe (20), a second regulating valve (24) is arranged on the liquid oxygen delivery branch pipe (20) between the supercooler (19) and the liquid oxygen storage tank (21), a first temperature sensor (25) is arranged on the liquid oxygen delivery branch pipe (20) between the liquid oxygen delivery branch pipe (20) and the liquid oxygen storage tank (21), the liquid oxygen storage tank (21) is provided with a liquid oxygen product delivery pipe (26), the liquid oxygen product delivery pipe (26) is provided with a liquid oxygen delivery pump (27) and a second temperature sensor (28).

5. The apparatus of claim 3, wherein: The outlet end of the third liquid nitrogen delivery pipe (18), the outlet end of the second liquid nitrogen delivery pipe (13) and the main heat exchanger (11) are provided with a second backflow nitrogen delivery pipe (29), the nitrogen delivery main pipe (1) between the inlet end of the nitrogen delivery main pipe (1) and the first nitrogen compressor (3) is communicated with the outlet end of the second backflow nitrogen delivery pipe (29), the outlet end of the first throttle valve (10) is further provided with the inlet end of a fourth liquid nitrogen delivery pipe (30), the second backflow nitrogen delivery pipe (29) between the main heat exchanger (11) and the nitrogen delivery main pipe (1) is communicated with the outlet end of the fourth liquid nitrogen delivery pipe (30).

6. The apparatus of claim 5, wherein: The fourth liquid nitrogen delivery pipe (30) between the first throttle valve (10) and the main heat exchanger (11), the third liquid nitrogen delivery pipe (18) between the first throttle valve (10) and the supercooler (19) and the second liquid nitrogen delivery pipe (13) between the first throttle valve (10) and the nitrogen liquefier (14) are respectively provided with a second throttle valve (31), the first pressure nitrogen shunt pipe (6) between the main heat exchanger (11) and the expansion end of the second turbine expander (8), the second pressure nitrogen shunt pipe (9) and the first liquid nitrogen delivery pipe (12) between the supercooler (19) and the liquid nitrogen storage tank (2) are respectively provided with a third regulating valve (32), and the first liquid nitrogen delivery pipe (12) between the supercooler (19) and the liquid nitrogen storage tank (2) is provided with a third temperature sensor (33).

7. The apparatus of claim 1, wherein: The nitrogen liquefaction pipe (15) between the nitrogen liquefier (14) and the liquid nitrogen storage tank (2) is sequentially provided with a fourth temperature sensor (34) and a liquid nitrogen booster pump (35) in the direction from the nitrogen liquefier (14) to the liquid nitrogen storage tank (2), and the nitrogen liquefaction pipe (15) between the liquid nitrogen booster pump (35) and the liquid nitrogen storage tank (2) is communicated with the outlet end of the first liquid nitrogen delivery pipe (12).

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