Energy-saving micro-rectifying tower air separation method and equipment

Abstract

The application discloses an energy-saving micro-rectifying tower air separation device, which comprises a rectifying tower, a heat closed loop system, a molecular sieve tank and a gas storage bottle group, the diameter of the rectifying tower is less than or equal to 80 mm, the rectifying tower comprises a condenser section at the top of the rectifying tower, a filler section at the middle of the rectifying tower and a reboiler section at the bottom of the rectifying tower, and the filler section comprises fillers arranged in an inner layer, guide plates arranged in an outer layer and grooves arranged on an inner wall. The application also discloses an energy-saving micro-rectifying tower air separation method. The method and the device are suitable for the fields of emergency medical treatment, vehicle-mounted gas production and distributed energy, and provide a high-energy-efficiency and high-reliability solution for micro-rectifying tower air separation devices.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air separation technology, in particular to an energy-saving micro-sized rectification column air separation method and equipment. BACKGROUND

[0002] Air separation equipment, referred to as "air separation equipment", is a core equipment for separating components such as oxygen, nitrogen, argon, etc. in air, and is widely used in medical treatment, chemical industry, metallurgy, aerospace, etc. The existing air separation technology is mainly divided into the following categories:

[0003] (1) Large-scale low-temperature rectification air separation technology, the principle of which is to liquefy air by deep freezing and to separate it by multi-stage rectification according to the difference in boiling points of components (oxygen boiling point -183℃, nitrogen boiling point -196℃). The disadvantage is that the equipment is bulky, occupying more than hundreds of square meters of land, and weighing several tons; it takes a long time to start up, requiring tens of hours of pre-cooling and system debugging, and cannot meet the emergency demand. The comprehensive energy consumption is 0.5-1.0 kWh / Nm³, which is only suitable for fixed large-scale production scenes.

[0004] (2) Pressure swing adsorption (PSA, Pressure Swing Adsorption) air separation technology, the principle of which is to use the selective adsorption characteristics of molecular sieve and other adsorbents to oxygen / nitrogen, and to realize cyclic separation by pressure change. The disadvantage is that the energy consumption is higher, the comprehensive energy consumption is 1.2-1.8 kWh / Nm³, which is significantly higher than that of low-temperature rectification technology; the purity is insufficient, the nitrogen purity is usually ≤99.5%, and the oxygen purity is ≤93%, which is difficult to meet the high-purity demand (such as medical oxygen ≥99.5%). And the equipment stability and reliability are poor, and the adsorption time and regeneration cycle need to be frequently adjusted.

[0005] (3) Membrane separation air separation technology, the principle of which is to rely on the difference in permeation rate of high molecular membrane to gas to realize separation. The disadvantage is that the separation efficiency is low, the oxygen recovery rate is <60%, and the purity is only suitable for low-demand scenes (such as oxygen-rich ventilation). Thus it cannot meet the demand of high-purity gas, the market adaptability is narrow, and the application scene is limited.

[0006] At present, with the rise of emergency medical treatment, vehicle-mounted oxygen production, distributed energy, etc., the demand for micro-sized air separation equipment (volume <1m³, weight <200kg) has surged. However, the traditional large-sized air separation technology mainly faces the following problems after being miniaturized:

[0007] (1) The separation efficiency is reduced after miniaturization. After the low-temperature rectification column is miniaturized (diameter <100mm), the gas-liquid distribution is uneven, resulting in a decrease in mass transfer efficiency and a reduction of 30%-50% in theoretical plate number, making it difficult to achieve efficient separation. After the pressure swing adsorption equipment is miniaturized, the adsorbent filling amount is limited, and the cycle period is shortened.

[0008] (2) After miniaturization, the energy consumption of separation increases, the energy consumption bottleneck intensifies, and the efficiency decreases. After miniaturization of the low-temperature rectification tower, the cold loss increases sharply with the reduction of the equipment, and the energy consumption of the large-scale equipment increases by more than 50%. After miniaturization of the pressure swing adsorption equipment, the energy utilization rate is less than 40% due to frequent valve switching and adsorbent regeneration.

[0009] (3) Single function. The existing small and micro devices can only produce high-purity oxygen or nitrogen, and cannot flexibly switch product types, making it difficult to adapt to multiple scene requirements.

[0010] (4) Starting speed and stability problems. The low-temperature rectification tower technology requires several hours of pre-cooling for starting, which cannot meet the immediate needs of medical first aid and the like. The pressure swing adsorption technology requires frequent adjustment of adsorption time, and the system stability is poor.

[0011] Therefore, the existing air separation technology cannot meet the requirements of miniaturization, low energy consumption, high purity and multi-scene adaptability, and a new type of air separation equipment is urgently needed to break through the existing technical bottlenecks. SUMMARY

[0012] In view of the above defects of the prior art, the present application improves the integrated micro rectification tower, heat recovery system and other technical means, and proposes an energy-saving micro rectification tower air separation method and equipment.

[0013] The first purpose of the present application is to propose an energy-saving micro rectification tower air separation equipment, which comprises a rectification tower, a heat closed loop system, a molecular sieve tank and a gas storage bottle group, characterized in that the diameter of the rectification tower is less than or equal to 80 mm, the rectification tower comprises a condenser section at the top of the rectification tower, a filler section in the middle of the rectification tower and a reboiler section at the bottom of the rectification tower; the filler section comprises fillers arranged in the inner layer of the filler section, guide plates arranged in the outer layer of the filler section and grooves arranged in the inner wall of the filler section.

[0014] Preferably, the specific surface area of the filler is greater than or equal to 800 m² / m³; the filler is a metal wire mesh ring with a diameter of 2-3 mm, or a three-dimensional printed filler with a spiral channel or a biomimetic fractal structure.

[0015] Preferably, the guide plate is a spiral guide plate, the spiral spacing is 8-12 mm, and the spiral angle is 40°-50°.

[0016] Preferably, the groove is a spiral groove, the groove depth is 0.3-0.5 mm, the groove spiral spacing is 1.5-2.5 mm, the groove spiral angle is 40°-50°, the inner wall roughness of the groove is less than or equal to 0.8 μm, the liquid holding capacity of each circle of the groove is less than 3 mL, and the gas-liquid contact time is greater than or equal to 1.5 seconds.

[0017] Preferably, the heat closed loop system comprises a heat pump unit, a heat conducting oil pipeline, a refrigerant pipeline and a control valve group, the heat conducting oil pipeline connects the condenser section, the heat pump unit and the reboiler section, and the refrigerant pipeline is arranged in the heat pump unit.

[0018] Preferably, the heat pump unit is a micro vortex heat pump unit with a power less than or equal to 80 W, and the heat pump unit is arranged at the top of the rectifying tower.

[0019] Preferably, the pre-cooling system further comprises a liquid nitrogen pre-charged cold accumulator.

[0020] Preferably, the condenser section, the packing section and the reboiler section are sequentially connected through flanges.

[0021] The second object of the present application provides an energy-saving micro-sized rectifying tower air separation method, comprising the following steps:

[0022] S1, setting the gas collection mode as an oxygen collection mode or a nitrogen collection mode;

[0023] S2, setting the operation pressure range and the reflux ratio range according to the gas collection mode;

[0024] S3, selecting the gas flow path according to the gas collection mode;

[0025] S4, starting the rectifying tower and pre-cooling;

[0026] S5, detecting the gas purity index, and starting to collect the gas after the index meets the standard;

[0027] S6, dynamically adjusting and optimizing the parameters to ensure that the gas purity index continuously meets the standard, the parameters including the reflux ratio, the operation pressure, the temperature and the heat pump unit power;

[0028] S7, changing the gas collection mode and switching the gas flow path when the gas needs to be replaced;

[0029] S8, detecting the gas purity index under the new gas collection mode, and starting to collect the gas after the index meets the standard.

[0030] Preferably, the S2 comprises:

[0031] (1) in the oxygen collection mode, the operation pressure range is 1.0-1.2 bar, and the reflux ratio range is 3-5;

[0032] (2) in the nitrogen collection mode, the operation pressure range is 1.5-2.0 bar, and the reflux ratio range is 1-2.

[0033] The energy-saving micro-sized rectifying tower air separation device provided by the present application has the following beneficial effects:

[0034] (1) Energy consumption and operating cost. The micro air separation device cooperates with the heat pump unit to form a heat closed loop system, and the heat pump unit recovers the condensation heat at the top of the tower and the waste heat at the bottom, which can improve the cold utilization rate to 85%, significantly reduce the external energy input, and reduce the comprehensive energy consumption to 0.58 kWh / Nm³, which is 60% lower than the traditional pressure swing adsorption PSA technology (1.2-1.8 kWh / Nm³) and 55% lower than the traditional micro distillation technology (1.3-1.5 kWh / Nm³).

[0035] (2) High-purity product, meet high-end demand. The output nitrogen purity reaches 99.99% (PSA technology is usually ≤99.5%), which is suitable for semiconductor manufacturing, food packaging and other high-purity demand scenarios. The output oxygen purity reaches 96% (PSA technology is usually ≤93%), which meets the requirements of medical emergency, oxygen-enriched combustion and other scenarios.

[0036] (3) Micro device, adapt to multiple scenarios. The device is small in size and can be deployed in the trunk of a vehicle, a container or a laboratory bench. The device weighs ≤150 kg (traditional device ≥500 kg), supports forklift handling and rapid deployment, and can provide instant high-purity oxygen for emergency medical vehicles.

[0037] (4) Extremely fast start, respond to emergency demand. The total start-up time is ≤15 minutes (traditional cryogenic rectification requires several hours). The liquid nitrogen pre-charged cold accumulator shortens the tower pre-cooling time to 10 minutes. The heat pump unit system starts simultaneously, and the temperature gradient required for rectification is established within 5 minutes. It meets the stringent requirements of medical emergency, disaster rescue and other devices for rapid response.

[0038] The present application breaks through the contradiction between the traditional air separation device in miniaturization, energy efficiency and purity, and takes miniaturization design, ultra-low energy consumption, high-purity output and extremely fast response as the core advantages, which can be widely used in emergency medical treatment, vehicle-mounted gas production, distributed energy and other fields, significantly reducing the user equipment investment and operating cost, and promoting the development of air separation technology to green, intelligent and diversified direction. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The step diagram of the air separation method of the embodiment of the present application;

[0040] Figure 2 The rectification tower principle diagram of the air separation device of the embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0042] Embodiment one

[0043] The energy-saving micro-sized rectifying column air separation device in the embodiment of the present application comprises a rectifying column, a hot closed loop system, a molecular sieve tank, a gas storage bottle group and the like.

[0044] The core of the air separation device is a micro-sized rectifying column, and the working principle is as shown in Figure 2 In the embodiment of the present application, the column body has a diameter of 60-80 mm and a total height of 1.2-1.5 m.

[0045] Due to the large volume of an industrial large-sized rectifying column, a welding method is usually used for fixed connection in view of the sealing requirement. The micro-sized rectifying column in the embodiment of the present application adopts a three-section detachable structure, and each section can be connected through a flange. The flange connection is more suitable for the micro-sized rectifying column, not only has good sealing performance, but also can be conveniently disassembled and cleaned when being operated for more than six months.

[0046] The micro-sized rectifying column comprises three sections which can be combined in sections:

[0047] (1) a condenser section located at the top of the rectifying column.

[0048] (2) a packing section located at the middle of the rectifying column;

[0049] (3) a reboiler section located at the bottom of the rectifying column.

[0050] The theoretical plate number of the rectifying column is an important parameter for measuring the separation capacity of the rectifying column. When the plate number increases, more mass transfer sites can be provided, and the separation efficiency is improved. The theoretical plate number of the micro-sized air separation device in the embodiment of the present application can reach 35-40 pieces. The micro-sized rectifying column adopts the following technical measures to reduce the wall effect and channeling:

[0051] (1) The inner layer of the packing section is filled with packing with a high specific surface area to provide a high-density mass transfer interface. The packing can be selected from:

[0052] (a) a wire mesh ring packing with a diameter of 2-3 mm and a specific surface area ≥800 m² / m³, which is much larger than that of a traditional Pall ring (110 m² / m³). The woven structure of the wire mesh ring forms a large number of micron-sized pores, and a gas-liquid film is formed on the surface of the wire mesh ring, which significantly increases the contact area and provides more gas-liquid contact interfaces.

[0053] (b) 3D printing filler, manufacturing complex flow channel structure by 3D printing technology. For example, printing titanium alloy powder by selective laser melting process, forming spiral channel or bionic fractal structure, improving specific surface area up to 800-1200 m² / m³, solving the problem of uneven fluid distribution in micro column, realizing uniform fluid distribution and low pressure drop, and improving theoretical plate number.

[0054] (2) The outer layer of the filler section is nested with spiral guide plates. The gas-liquid two-phase generates Coriolis force in the spiral flow channel, forcing the gas-liquid to mix laterally, breaking the one-way flow pattern, and improving the mass transfer efficiency. The spiral guide plate can have a spacing of 8-12 mm, preferably 10 mm. The spiral angle is 40°-50°, preferably 45°, and the column body forms a three-dimensional spiral flow channel along the axis direction.

[0055] (3) The inner wall of the filler section is processed with micron-level grooves, which can be processed by laser engraving process. The groove depth is 0.3-0.5 mm, preferably 0.4 mm. The groove spacing is 1.5-2.5 mm, preferably 2 mm. The groove spiral angle is 45°±5°, and the liquid holdup per groove is <3 mL, and the gas-liquid contact time is ≥1.5 s. The roughness of the engraved inner wall is Ra≤0.8 μm, and the inner wall forms a super-hydrophobic surface to reduce liquid film retention. The rectifying column forms a "uniform wall film distribution-center gas core stable rising" double-region flow pattern, which suppresses the channel flow and strengthens the uniformity of the flow field.

[0056] The heat closed loop system of the embodiment of the present application includes a heat pump unit and a pipeline, the pipeline including a heat conducting oil pipeline and a refrigerant pipeline. The heat conducting oil pipeline connects the heat pump unit, a condenser located at the top of the rectifying column, and a reboiler at the bottom of the rectifying column, forming a cold and heat recovery closed loop. The heat conducting oil circulation pipeline adopts a stainless steel corrugated pipe, which is covered with a heat preservation layer to reduce cold loss. The refrigerant pipeline is independent of the heat conducting oil system and only circulates inside the heat pump unit to complete the refrigerant "compression-condensation-evaporation" process.

[0057] The heat pump unit of the embodiment of the present application is a miniature scroll heat pump unit with a power of ≤80 W, which can be arranged beside the condenser at the top of the column. The design of integrating the heat pump unit at the top of the rectifying column shortens the connecting pipeline of the heat pump and the condenser and the reboiler, reduces the space occupation, and meets the needs of miniaturized equipment. The functions of the heat pump unit include:

[0058] (1) Condensation heat recovery at the top of the column.

[0059] The condenser at the top of the column generates low-temperature condensation heat (-190 ℃ level cold, temperature range: -190 ℃ to -180 ℃). The heat pump unit raises this cold to medium temperature -170 ℃ to -160 ℃ through refrigerant circulation, which is used to pre-cool the raw material air entering the rectifying column, reducing the demand for external cold source.

[0060] (2) Upgrading of the waste heat at the bottom of the column.

[0061] The reboiler generates low-temperature waste heat (heat at -180℃, temperature range: -180℃ to -170℃), and the heat pump unit increases the temperature of the heat to -160℃ to -150℃, which is used to heat the tower bottom reflux liquid, reduces the demand for external heat source, and improves the distillation efficiency.

[0062] The COP (Coefficient Of Performance, refrigeration coefficient) of the heat closed loop system in the embodiment of the present application reaches 3.0-3.5, that is, 3.0-3.5 kW of heat can be transferred per consumption of 1 kW of electric energy, and the overall energy consumption of the air separation device is reduced by 55% compared with the traditional micro-distillation.

[0063] The air separation device in the embodiment of the present application further comprises a pre-cooling system for quickly reaching the distillation temperature condition after the air separation device is started. Preferably, the pre-cooling system can adopt a liquid nitrogen pre-charged type cold accumulator, and the capacity can be set to 5L. The distillation temperature condition can be reached within 10 minutes after the air separation device is started, and qualified gas can be produced within 15 minutes after the air separation device is started.

[0064] The air separation device in the embodiment of the present application further comprises a molecular sieve tank, wherein a molecular sieve adsorber is arranged. The raw air enters the air separation device, is first pre-cooled (cooled to -185℃) by the heat pump, then removes water molecules and carbon dioxide molecules in the raw air by the molecular sieve adsorber, and then enters the middle part of the rectification tower.

[0065] The rectification tower, the heat closed loop system, the molecular sieve tank, the gas storage bottle group and the like in the embodiment of the present application can be integrated in an integrated frame, the frame size can be 800x600x1200mm, the overall volume is 0.58m³, the overall weight is ≤150kg, the forklift can be supported, the vehicle-mounted and container type deployment can be supported, and the embodiment is suitable for medical oxygen production, industrial nitrogen production, emergency gas supply and the like.

[0066] Embodiment two

[0067] The industrial large-scale rectification tower air separation device usually adopts a double-tower structure, and can generate oxygen and nitrogen at the same time. The micro-distillation tower air separation device is limited by the physical constraints of the miniaturized design, and can usually only output one kind of high-purity oxygen or nitrogen.

[0068] The micro-distillation tower (tower diameter ≤80mm) in the embodiment of the present application, although the mass transfer is optimized through high specific surface area packing and spiral grooves, the physical size limitation still leads to a theoretical plate number (35-40 plates) lower than that of the industrial double-stage rectification tower (usually hundreds of theoretical plates), and it is difficult to realize simultaneous separation of high-purity multiple components. The micro-distillation tower in the embodiment of the present application supports switching to oxygen production mode or nitrogen production mode by adjusting operating pressure and reflux ratio and the like. In the oxygen production mode, the reboiler temperature is increased to enhance oxygen resolution; in the nitrogen production mode, the condenser temperature is reduced to strengthen nitrogen enrichment, so as to output high-purity gas.

[0069] An energy-saving micro-sized rectification tower air separation method according to an embodiment of the present application, as shown in the figure, comprises the following steps: Figure 1

[0070] S1, set the gas collection mode.

[0071] The device starts the self-checking process, including checking the valve state, whether the pre-cooling system is normal, etc. Select the target gas type as oxygen or nitrogen through the control panel, and set the air separation device gas collection mode as oxygen collection mode or nitrogen collection mode.

[0072] S2, set the operating pressure and reflux ratio range.

[0073] In the embodiment of the present application, in the oxygen collection mode, the operating pressure range is 1.0-1.2 bar, and the reflux ratio range is 3-5. In the nitrogen collection mode, the operating pressure range is 1.5-2.0 bar, and the reflux ratio range is 1-2. The pressure range can also be adjusted according to the ambient temperature, for example, the pressure can be floated by 0.1-0.2 bar in a high-temperature environment.

[0074] The operating pressure controlled in the embodiment of the present application improves the gas purity. The boiling point of oxygen (-183℃) is higher than that of nitrogen (-196℃). In the oxygen collection mode, the lower operating pressure can reduce the gas phase partial pressure in the tower, so that oxygen is more easily condensed in the overhead condenser, while nitrogen remains in the gas phase. This design can realize effective separation of oxygen without extremely high pressure, while reducing the pressure-bearing requirement of the equipment, and is suitable for micro-sized rectification towers. In the nitrogen collection mode, the relative volatility of nitrogen and oxygen decreases with the increase of pressure. In order to improve the purity of nitrogen, the enrichment of nitrogen at the tower bottom needs to be strengthened by increasing the pressure. In a high-pressure environment, the solubility of nitrogen molecules in the liquid phase decreases, and they are more easily volatilized into the gas phase, thereby increasing the concentration of nitrogen at the tower bottom.

[0075] The reflux ratio controlled in the embodiment of the present application improves the gas purity. In the oxygen collection mode, oxygen separation needs to strengthen the mass transfer efficiency through high reflux ratio. High reflux ratio means that more liquid phase returns to the tower from the top, ensuring that oxygen is fully condensed and precipitated in the packing section. In addition, oxygen condensation needs to rely on the heat pump unit to recover the cold energy, and high reflux ratio can match the cold energy supply of the heat pump to maintain the heat balance of the rectification tower. If the reflux ratio is too low, the oxygen purity may decrease. In the nitrogen collection mode, nitrogen separation relies on the pressure swing rectification process, and the separation time is shortened by increasing the pressure. At this time, the enrichment efficiency of nitrogen at the tower bottom is higher, and lower reflux ratio can meet the separation requirement. Reducing the reflux ratio can reduce the liquid phase circulation amount and the load of the heat pump unit (because the tower bottom needs to be heated for nitrogen separation), thereby optimizing the system energy consumption.

[0076] S3, switch the gas flow path using a switching valve.

[0077] ​The three-way switch valve is sent a signal by the electronic control system to switch the gas flow path. Anti-impact measures can be taken, such as gradually reducing the gas source pressure through a pressure reducing valve before switching to avoid sudden changes in gas flow, or adding a buffer cylinder to the valve body and extending the action time to 10-20 seconds. For the three-way switch valve, the valve shaft seal needs to be checked regularly, for example, the packing is replaced every quarter.

[0078] S4, start the rectifying column, and the liquid nitrogen pre-charged cold accumulator pre-cools the rectifying column.

[0079] The heat conducting oil circulation flow rate can be adjusted according to the size of the column body and set to 5-8 L / min. The temperature is controlled, and the inlet temperature of the heat conducting oil during the pre-cooling stage is ≤-180℃, and the outlet temperature is ≥-170℃. The pre-cooling completion degree is detected by the column body surface temperature sensor.

[0080] S5, detect the gas purity index, and start collecting gas after the index meets the standard.

[0081] The nitrogen purity is detected by the nitrogen purity sensor arranged at the outlet pipeline of the condenser at the top of the rectifying column. The oxygen purity is detected by the oxygen purity sensor arranged at the inlet pipeline of the reboiler at the bottom. When the purity index meets the standard, the gas collection is started. The embodiment of the present application can output oxygen with a purity of ≥96% and nitrogen with a purity of ≥99.99%.

[0082] S6, dynamically adjust and optimize parameters to ensure that the gas purity index meets the standard, including reflux ratio, heat pump unit pre-cooling power, operating pressure, temperature, etc.

[0083] The MPC (Model Predictive Control) algorithm or other methods can be used to adjust the control parameters such as pressure, reflux ratio, and heat pump unit power according to the purity data. The operating pressure is based on the set value with a fluctuation range of ±0.02 bar. The reflux ratio adjustment step is ≤0.1 each time to avoid excessive oscillation.

[0084] S7, when it is necessary to switch the gas collection mode, the gas flow path is switched by the switching valve.

[0085] The current gas inlet valve of the gas cylinder is closed, the current gas collection mode is stopped, the electronic expansion valve and the three-way switch valve are operated, and the parameters are adjusted to adjust the pressure / reflux ratio to the set value of the new mode. The waiting period after mode switching is about 5 minutes.

[0086] S8, detect the purity index in the new gas collection mode, and start collecting new gas after the index meets the standard.

[0087] The purity detection process of step S5 is repeated, and after the purity of the new gas type meets the standard, the new gas collection is started.

[0088] The air space method of the embodiment of the present application can complete the collection and switching of oxygen or air through the above S1-S8 steps.

[0089] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the technical principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An energy-saving miniaturized distillation column air separation unit, comprising a distillation column, a thermal closed-loop system, a molecular sieve tank, a gas storage cylinder group, and a precooling system, characterized in that, The distillation column has a diameter of 80 mm or less and includes a condenser section at the top, a packing section in the middle, and a reboiler section at the bottom. The condenser section, packing section, and reboiler section are connected in sequence by flanges. The packing section includes packing material in the inner layer, a guide plate in the outer layer, and grooves on the inner wall of the packing section. The precooling system includes a liquid nitrogen pre-charged accumulator.

2. The air separation equipment according to claim 1, characterized in that, The specific surface area of ​​the filler is greater than or equal to 800 m² / m³; the filler is a metal wire mesh ring with a diameter of 2-3 mm, or a three-dimensional printed filler with a spiral channel or a biomimetic fractal structure.

3. The air separation equipment according to claim 1, characterized in that, The guide plate is a spiral guide plate with a spiral spacing of 8-12mm and a spiral angle of 40°-50°.

4. The air separation equipment according to claim 1, characterized in that, The groove is a spiral groove with a depth of 0.3-0.5 mm, a spiral spacing of 1.5-2.5 mm, a spiral angle of 40°-50°, an inner wall roughness of less than or equal to 0.8 μm, a liquid holding capacity of less than 3 mL per groove turn, and a gas-liquid contact time of greater than or equal to 1.5 seconds.

5. The air separation equipment according to claim 1, characterized in that, The thermal closed-loop system includes a heat pump unit, a heat transfer oil pipeline, a refrigerant pipeline, and a control valve group. The heat transfer oil pipeline connects the condenser section, the heat pump unit, and the reboiler section, and the refrigerant pipeline is located inside the heat pump unit.

6. The air separation equipment according to claim 5, characterized in that, The heat pump unit is a micro scroll heat pump unit with a power of less than or equal to 80W, and the heat pump unit is installed at the top of the distillation column.

7. An air separation method based on the energy-saving miniaturized distillation column air separation equipment according to claim 1, characterized in that, Includes the following steps: S1. Set the gas extraction mode to oxygen extraction mode or nitrogen extraction mode; S2. Based on the gas extraction mode, set the operating pressure range and reflux ratio range; S3. Select the gas flow path according to the gas extraction mode; S4. Start the distillation column and precool it; S5. Check the purity of the gas sampled; once the standard is met, begin collecting the gas. S6. Dynamically adjust and optimize parameters to ensure that the gas purity index continuously meets the standards. The parameters include reflux ratio, operating pressure, temperature and heat pump unit power. S7. When it is necessary to change the gas, change the gas sampling mode and switch the gas flow path; S8. Detect the gas purity index under the new gas extraction mode. Once the index is met, start collecting gas.

8. The air separation method according to claim 7, characterized in that, S2 includes: (1) In oxygen sampling mode, the operating pressure range is 1.0-1.2 bar, and the reflux ratio range is 3-5; (2) In nitrogen sampling mode, the operating pressure range is 1.5-2.0 bar and the reflux ratio range is 1-2.

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