Air separation system

Abstract

The invention relates to an air separation system which comprises an energy storage unit, air is pressurized through a first compression device to generate heat, and the heat is taken away by a first cooling device to be used for providing heat for a heating device. Air pressurized and cooled by the first compression device and the first cooling device is cooled by the second cooling device and further cooled by the second low-temperature expansion machine to generate a liquid phase which enters the gas-liquid separation device, and a liquid phase outlet of the gas-liquid separation device is connected with the heating device and the power generation device; a gas phase outlet of the gas-liquid separation device is connected with a rectifying tower through a first heat exchanger, and a liquid phase outlet of the rectifying tower is connected with an air separation tank through a second heat exchanger and a throttling valve in sequence. The energy storage unit is coupled with the air separation unit, and resources are fully utilized.

Description

Technical Field

[0001] The present disclosure relates to the technical field of air separation, and in particular, to an air separation system. Background Art

[0002] Compressed air energy storage technology is to liquefy compressed air after cooling, throttling or expansion, which can greatly increase the air density, reduce the gas storage volume, and thus increase the energy storage density. The principle of the air cryogenic separation method relies on the difference in boiling points of various components in the air at different temperatures. This physical property allows these components to be effectively separated through a series of process steps. This method has broad application prospects in industrial production.

[0003] In the related art, compressed air energy storage and air cryogenic separation are both separately configured, which cannot fully utilize resources and will result in waste of resources. Summary of the invention

[0004] The purpose of the present disclosure is to provide an air separation system, which can solve the above-mentioned technical problems.

[0005] In order to achieve the above-mentioned purpose, the present disclosure provides an air separation system, comprising: an energy storage unit, comprising a gas-liquid separation device, a first compression device, a first cooling device, a second cooling device, a second low-temperature expander, a heating device and a power generation device, wherein the air is pressurized by the first compression device to generate heat, and the heat is taken away by the first cooling device to provide heat for the heating device, and the air pressurized and cooled by the first compression device and the first cooling device is cooled by the second cooling device and further cooled by the second low-temperature expander to generate a liquid phase and enter the gas-liquid separation device, and the liquid phase outlet of the gas-liquid separation device is connected to the heating device and the power generation device; and an air separation unit, comprising a distillation tower, an air separation separation tank, a first heat exchanger and a second heat exchanger, wherein the gas phase outlet of the gas-liquid separation device is connected to the distillation tower through the first heat exchanger, and the liquid phase outlet of the distillation tower is connected to the air separation separation tank through the second heat exchanger and the throttle valve in sequence.

[0006] Optionally, the gas phase outlet of the distillation tower is connected to the cold end of the first heat exchanger to provide a cold source for the first heat exchanger, and the gas phase outlet of the air separation tank is connected to the cold ends of the second heat exchanger and the first heat exchanger in sequence to provide a cold source for the second heat exchanger and the first heat exchanger.

[0007] Optionally, the air separation unit further comprises a first low-temperature expander, and the cold end outlet of the first heat exchanger is connected to the second heat exchanger and the cold end of the first heat exchanger again and discharged after being reduced in pressure and temperature by the first low-temperature expander.

[0008] Optionally, the air separation unit further comprises a mixer, one inlet of the mixer is connected to the gas phase outlet of the gas-liquid separation device, the other inlet is connected to the outside for gas replenishment, and the outlet of the mixer is connected to the hot end of the first heat exchanger.

[0009] Optionally, the air separation unit further includes a first splitter and a second compression device, the outlet of the mixer is connected to the inlet of the first splitter through the second compression device, one of the outlets of the first splitter is connected to the hot end of the first heat exchanger, and the other outlet is connected to the outside for exhaust.

[0010] Optionally, the gas phase outlet of the gas-liquid separation device is connected to one of the cold end inlets of the second cooling device, and the cold end outlet corresponding to the cold end inlet is connected to one of the inlets of the mixer.

[0011] Optionally, the energy storage unit also includes an evaporator, which is arranged between the liquid phase outlet of the gas-liquid separation device and the heating device, and the hot end outlet of the evaporator is connected to one of the cold end inlets of the second cooling device, and the cold end outlet corresponding to the cold end inlet is connected to the hot end inlet of the evaporator.

[0012] Optionally, the energy storage unit also includes a hot oil tank for storing heat, and multiple first compression devices are provided in series, and the outlet of each first compression device is connected to the first cooling device, the cold end outlet of the first cooling device is connected to the inlet of the hot oil tank, and the outlet of the hot oil tank is connected to the heating device.

[0013] Optionally, the energy storage unit also includes a cold oil tank for storing cold, the power generation device is constructed as a steam turbine, and multiple steam turbines are arranged in series, the inlet of each steam turbine is connected to the heating device, the hot end of the heating device is connected to the inlet of the cold oil tank, and the outlet of the cold oil tank is connected to the cold end of the first cooling device.

[0014] Optionally, the energy storage unit also includes a second diverter, the inlet of the second diverter is connected to the liquid phase outlet of the gas-liquid separation device, one of the outlets of the second diverter is connected to the cold end inlet of the evaporator through a first cryogenic pump, and the other outlet is connected to the air separation tank through a second cryogenic pump.

[0015] Through the above technical scheme, in the energy storage stage, the air is compressed by the first compression device to form a high-pressure and high-temperature state, and the heat generated in the compression process is taken away by the first cooling device to provide heat for the heating device. The cooled high-pressure and normal-temperature air is cooled by the second cooling device and further cooled by the second low-temperature expander to produce a liquid phase and then enters the gas-liquid separation device for gas-liquid separation; in the air separation stage, the nitrogen-rich gas generated by the gas-liquid separation device is used as the raw gas for air separation, and then cooled by the first heat exchanger and enters the distillation tower for distillation. The liquid phase air produced at the liquid phase outlet of the distillation tower is cooled by the second heat exchanger and then reduced in pressure and temperature by the throttle valve to enter the air separation separation tank, and together with a small part of the liquid phase air from the gas-liquid separation device, it is used as the raw material of the air separation separation tank. The energy storage unit is coupled with the air separation unit to make full use of resources.

[0016] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings: Figure 1 It is a schematic diagram of the structure of the air separation system in the present disclosure.

[0018] Description of Reference Numerals 1. First compression device; 2. First cooling device; 3. Second cooling device; 4. Second cryogenic expander; 5. Gas-liquid separation device; 6. Second flow divider; 7. First cryogenic pump; 8. Evaporator; 9. Heating device; 10. Power generation device; 11. Cold oil tank; 12. Hot oil tank; 13. Mixer; 14. Second compression device; 15. First flow divider; 16. First heat exchanger; 17. Distillation tower; 18. Second heat exchanger; 19. Throttle valve; 20. Air separation separation tank; 21. Second cryogenic pump; 22. First cryogenic expander; 100. Energy storage unit; 200. Air separation unit. DETAILED DESCRIPTION

[0019] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0020] In the present disclosure, unless otherwise stated, the directional words used, such as "inside" and "outside", refer to the inside and outside relative to the outline of the component or structure itself. In addition, it should be noted that the terms used, such as "first" and "second", etc., are used to distinguish one element from another element and do not have order and importance. In addition, in the description with reference to the drawings, the same mark in different drawings represents the same element.

[0021] like Figure 1 As shown, the present disclosure provides an air separation system, including: an energy storage unit 100, including a gas-liquid separation device 5, a first compression device 1, a first cooling device 2, a second cooling device 3, a second low-temperature expander 4, a heating device 9 and a power generation device 10, the air is pressurized by the first compression device 1 to generate heat, and the heat is taken away by the first cooling device 2 to provide heat for the heating device 9, the air pressurized and cooled by the first compression device 1 and the first cooling device 2 is cooled by the second cooling device 3 and further cooled by the second low-temperature expander 4 to generate a liquid phase and enter the gas-liquid separation device 5, and the liquid phase outlet of the gas-liquid separation device 5 is connected to the heating device 9 and the power generation device 10; and an air separation unit 200, including a distillation tower 17, an air separation separation tank 20, a first heat exchanger 16 and a second heat exchanger 18, the gas phase outlet of the gas-liquid separation device 5 is connected to the distillation tower 17 through the first heat exchanger 16, and the liquid phase outlet of the distillation tower 17 is connected to the air separation separation tank 20 through the second heat exchanger 18 and the throttle valve 19 in sequence.

[0022] Through the above technical scheme, in the energy storage stage, the air is compressed by the first compression device 1 to form a high-pressure and high-temperature state, and the heat generated in the compression process is taken away by the first cooling device 2 to provide heat for the heating device 9. The cooled high-pressure and normal-temperature air is cooled by the second cooling device 3 and further cooled by the second low-temperature expander 4 to produce a liquid phase and then enters the gas-liquid separation device 5 for gas-liquid separation; in the air separation stage, the nitrogen-rich gas produced by the gas-liquid separation device 5 is used as the raw gas for air separation, and then cooled by the first heat exchanger 16 and enters the distillation tower 17 for distillation. The liquid phase air produced at the liquid phase outlet of the distillation tower 17 is cooled by the second heat exchanger 18 and then reduced in pressure and temperature by the throttle valve 19 and enters the air separation separation tank 20, and together with a small part of the liquid phase air from the gas-liquid separation device 5, it is used as the raw material of the air separation separation tank 2020. The energy storage unit 100 is coupled with the air separation unit 200 to make full use of resources.

[0023] As an optional embodiment, the gas phase outlet of the distillation tower 17 is connected to the cold end of the first heat exchanger 16 to provide a cold source for the first heat exchanger 16, and the gas phase outlet of the air separation separation tank 20 is connected to the second heat exchanger 18 and the cold end of the first heat exchanger 16 in sequence to provide a cold source for the second heat exchanger 18 and the first heat exchanger 16. After the distillation process of the distillation tower 17, gaseous nitrogen is produced at the top of the tower, a small part of which is condensed into liquid nitrogen by the condenser configured by the distillation tower 17 and then produced as a product; the remaining majority of the gaseous nitrogen is used as one of the cold sources of the first heat exchanger 16 to cool the air separation raw gas and then produced as a gaseous nitrogen product. The liquid phase outlet of the air separation separation tank 20 is connected to the outside world, and the gas phase outlet of the air separation separation tank 20 separates low-temperature gaseous air for the cold source of the first heat exchanger 16 and the second heat exchanger 18, so as to be fully utilized.

[0024] Optionally, the air separation unit 200 also includes a first low-temperature expander 22. The cold end outlet of the first heat exchanger 16 is connected to the second heat exchanger 18 and the cold end of the first heat exchanger 16 again and discharged after being reduced in pressure and temperature by the first low-temperature expander 22. The gaseous nitrogen is cooled in the first heat exchanger 16 and then reduced in pressure and temperature by the first low-temperature expander 22, and is used as a cold source for the first heat exchanger 16 and the second heat exchanger 18 again, and is discharged to the atmosphere after being fully cooled.

[0025] As an optional embodiment, the air separation unit 200 also includes a mixer 13, one of the inlets of the mixer 13 is connected to the gas phase outlet of the gas-liquid separation device 5, and the other inlet is connected to the outside for gas replenishment. The outlet of the mixer 13 is connected to the hot end of the first heat exchanger 16. The gas phase outlet of the gas-liquid separation device 5 produces nitrogen-rich gas. The nitrogen content in the air separation feed gas is reduced by replenishing gas from the external environment to ensure the safe and stable operation of the subsequent air separation process.

[0026] Optionally, the air separation unit 200 also includes a first splitter 15 and a second compression device 14. The outlet of the mixer 13 is connected to the inlet of the first splitter 15 through the second compression device 14. One of the outlets of the first splitter 15 is connected to the hot end of the first heat exchanger 16, and the other outlet is connected to the outside for exhaust. The air after neutralization of the nitrogen content is pressurized by the second compression device 14 and then discharged into the atmosphere through the first splitter 15 to match the cold capacity that can be used in the air separation part, thereby avoiding the problem of poor distillation effect caused by insufficient cold capacity.

[0027] Optionally, the gas phase outlet of the gas-liquid separation device 5 is connected to one of the cold end inlets of the second cooling device 3, and the cold end outlet corresponding to the cold end inlet is connected to one of the inlets of the mixer 13. The gas phase outlet of the gas-liquid separation device 5 produces low-temperature nitrogen-rich gas as a cold source for the second cooling device 3, which is used as raw gas for air separation after cooling.

[0028] As an optional embodiment, the energy storage unit 100 also includes an evaporator 8, which is arranged between the liquid phase outlet of the gas-liquid separation device 5 and the heating device 9. The hot end outlet of the evaporator 8 is connected to one of the cold end inlets of the second cooling device 3, and the cold end outlet corresponding to the cold end inlet is connected to the hot end inlet of the evaporator 8. The evaporator 8 heats the liquid phase air produced by the gas-liquid separation device 5, and the normal pressure air cooled by the liquid phase air serves as one of the cold sources of the second cooling device 3. After releasing the cold, the normal temperature air returns to the evaporator 8 again to evaporate the liquid phase air.

[0029] As an optional embodiment, the energy storage unit 100 also includes a hot oil tank 12 for storing heat. A plurality of first compression devices 1 are arranged in series, and the outlet of each first compression device 1 is connected to a first cooling device 2. The cold end outlet of the first cooling device 2 is connected to the inlet of the hot oil tank 12. The outlet of the hot oil tank 12 is connected to the heating device 9. The air undergoes multi-stage compression and multi-stage cooling. The heat generated by the compression is taken away by the first cooling device 2 after heat exchange with the heat transfer oil, and is stored in the hot oil tank 12 to provide heat for the heating device 9.

[0030] Optionally, the energy storage unit 100 also includes a cold oil tank 11 for storing cold. The power generation device 10 is constructed as a steam turbine. A plurality of steam turbines are arranged in series. A heating device 9 is connected to the inlet of each steam turbine. The hot end of the heating device 9 is connected to the inlet of the cold oil tank 11. The outlet of the cold oil tank 11 is connected to the cold end of the first cooling device 2. The liquid air generated by the liquid phase outlet of the gas-liquid separation device 5 is heated by the evaporator 8, and then heated step by step by multiple heating devices 9. The energy is released and electricity is generated by the step-by-step expansion of multiple steam turbines. After three stages of expansion, the energy in the high-pressure air is completely released. After the heat release of the heating device 9, the cold is carried away by the heat transfer oil and stored in the cold oil tank 11 to provide a cold source for the first cooling device 2.

[0031] As an optional embodiment, the energy storage unit 100 also includes a second diverter 6, the inlet of the second diverter 6 is connected to the liquid phase outlet of the gas-liquid separation device 5, one of the outlets of the second diverter 6 is connected to the cold end inlet of the evaporator 8 through the first cryogenic pump 7, and the other outlet is connected to the air separation separation tank 20 through the second cryogenic pump 21. A small part of the separated liquid air is pumped into the air separation separation tank 20 by the second cryogenic pump 21 as a source of cold for the air separation part, and most of it is used for liquid air evaporation and expansion to generate electricity. Most of the liquid air is pressurized to high pressure by the first cryogenic pump 7 and then pumped into the evaporator 8. After passing through the evaporator 8, the low-temperature and high-pressure liquid air becomes room-temperature and high-pressure air and enters the three-stage air turbine unit to generate power. The air turbine unit is equipped with a pre-stage heater before the stage to heat the room-temperature and high-pressure air to high-temperature and high-pressure air, thereby improving the work capacity.

[0032] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0033] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0034] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. An air separation system, characterized in that: include: The energy storage unit includes a gas-liquid separation device, a first compression device, a first cooling device, a second cooling device, a second low-temperature expander, a heating device and a power generation device. The air is pressurized by the first compression device to generate heat, and the heat is taken away by the first cooling device to provide heat for the heating device. The air pressurized and cooled by the first compression device and the first cooling device is cooled by the second cooling device and further cooled by the second low-temperature expander to generate a liquid phase that enters the gas-liquid separation device. The liquid phase outlet of the gas-liquid separation device is connected to the heating device and the power generation device. as well as The air separation unit comprises a distillation tower, an air separation separation tank, a throttle valve, a first heat exchanger and a second heat exchanger, wherein the gas phase outlet of the gas-liquid separation device is connected to the distillation tower through the first heat exchanger, and the liquid phase outlet of the distillation tower is connected to the air separation separation tank through the second heat exchanger and the throttle valve in sequence.

2. The air separation system according to claim 1, characterized in that The gas phase outlet of the distillation tower is connected to the cold end of the first heat exchanger to provide a cold source for the first heat exchanger, and the gas phase outlet of the air separation tank is connected to the cold ends of the second heat exchanger and the first heat exchanger in sequence to provide a cold source for the second heat exchanger and the first heat exchanger.

3. The air separation system according to claim 2, characterized in that The air separation unit further includes a first low-temperature expander. The cold end outlet of the first heat exchanger is connected to the second heat exchanger and the cold end of the first heat exchanger again and discharged after being reduced in pressure and temperature by the first low-temperature expander.

4. The air separation system according to claim 1, characterized in that The air separation unit also includes a mixer, one inlet of which is connected to the gas phase outlet of the gas-liquid separation device, the other inlet is connected to the outside for gas replenishment, and the outlet of the mixer is connected to the hot end of the first heat exchanger.

5. The air separation system according to claim 4, characterized in that The air separation unit also includes a first splitter and a second compression device. The outlet of the mixer is connected to the inlet of the first splitter through the second compression device. One of the outlets of the first splitter is connected to the hot end of the first heat exchanger, and the other outlet is connected to the outside for exhaust.

6. The air separation system according to claim 4, characterized in that The gas phase outlet of the gas-liquid separation device is connected to one of the cold end inlets of the second cooling device, and the cold end outlet corresponding to the cold end inlet is connected to one of the inlets of the mixer.

7. The air separation system according to claim 1 or 6, characterized in that: The energy storage unit also includes an evaporator, which is arranged between the liquid phase outlet of the gas-liquid separation device and the heating device. The hot end outlet of the evaporator is connected to one of the cold end inlets of the second cooling device, and the cold end outlet corresponding to the cold end inlet is connected to the hot end inlet of the evaporator.

8. The air separation system according to claim 1, characterized in that The energy storage unit also includes a hot oil tank for storing heat. A plurality of the first compression devices are connected in series. The outlet of each of the first compression devices is connected to the first cooling device. The cold end outlet of the first cooling device is connected to the inlet of the hot oil tank, and the outlet of the hot oil tank is connected to the heating device.

9. The air separation system according to claim 8, characterized in that The energy storage unit also includes a cold oil tank for storing cold. The power generation device is constructed as a steam turbine. A plurality of steam turbines are arranged in series. The inlet of each steam turbine is connected to the heating device. The hot end of the heating device is connected to the inlet of the cold oil tank, and the outlet of the cold oil tank is connected to the cold end of the first cooling device.

10. The air separation system according to claim 7, characterized in that The energy storage unit also includes a second diverter, the inlet of the second diverter is connected to the liquid phase outlet of the gas-liquid separation device, one of the outlets of the second diverter is connected to the cold end inlet of the evaporator through a first cryogenic pump, and the other outlet is connected to the air separation tank through a second cryogenic pump.

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