Space division equipment

Abstract

The utility model provides a kind of air separation equipment. Wherein, the first feeding pipeline of pipeline system is set to make the first feed after compression via compressor assembly expand through expander, then enter the low position of high pressure tower as ascending gas. Pipeline system includes additional pipeline. Throttle valve is arranged in additional pipeline. The inlet of additional pipeline is arranged at the shunt position of first feeding pipeline between expander and high pressure tower, and the outlet of additional pipeline is arranged at the intermediate position of low pressure tower. The above-mentioned air separation equipment can meet the strict equipment transportation size limit while trying to have less negative impact on energy consumption or yield.

Description

Technical Field

[0001] This utility model belongs to the field of air separation and relates to an air separation device. Background Technology

[0002] Cryogenic air separation is a recognized method for the large-scale industrial production of high-purity oxygen, nitrogen, and other substances. In a typical air separation unit (ASU), the feed air is compressed and purified, then cooled to a cryogenic temperature by the refluxed product stream in the main heat exchanger, and finally fed into a distillation column system for separation. The distillation column system can be a single column or multiple columns, such as a double column.

[0003] Currently, the industry commonly expands and cools at least a portion of the feed air before sending it into a high-pressure tower as rising gas to provide sufficient cooling capacity. For example, in Chinese invention patent CN111433545B, one portion of the feed air is pressurized, and the other portion is expanded, both of which then enter the high-pressure tower as rising gas.

[0004] However, when the above technologies are applied to the design and construction of modern large-scale air separation plants, the physical size limitations of key components become an issue.

[0005] Specifically, as the scale of individual air separation units continues to increase, the diameters of core components such as high-pressure columns, low-pressure columns, and main condenser-evaporators also increase. In many cases, the diameters of these components are strictly limited by transportation conditions between the manufacturing site and the project site, such as by road or sea.

[0006] Simply scaling down existing components to meet these transportation restrictions will inevitably lead to a decrease in the thermodynamic efficiency of the distillation process, resulting in increased energy consumption and reduced output.

[0007] Therefore, a new air separation unit is needed that can avoid or significantly reduce the impact on energy consumption or output while meeting strict equipment transport size restrictions. Utility Model Content

[0008] The purpose of this invention is to provide an air separation device that can minimize the negative impact on energy consumption or output while meeting strict equipment transportation size restrictions.

[0009] This invention provides an air separation unit, including a piping system and a distillation column system. The distillation column system includes a high-pressure column and a low-pressure column thermally connected by a main condenser-evaporator. The piping system includes a first feed line, configured such that the first feed, compressed by the compressor assembly, expands through an expander and then enters the lower section of the high-pressure column as rising gas. The piping system includes an auxiliary line, in which a throttling valve is installed. The inlet of the auxiliary line is located at the branch point of the first feed line between the expander and the high-pressure column, and the outlet of the auxiliary line is located at the middle position of the low-pressure column.

[0010] In one embodiment, the compressor assembly includes a booster compressor. The piping system is configured such that feed air is divided into a booster feed, which is pressurized by the booster compressor, and a bypass feed, which bypasses the booster compressor. At least a portion of the booster feed constitutes a first feed. The piping system also includes a feed bypass, configured such that the bypass feed, after being cooled by the main heat exchanger, also enters the lower part of the high-pressure tower as rising air. The first feed line is configured such that the first feed, after being cooled by the main heat exchanger, enters the expander for expansion. The compressor assembly also includes a main compressor, and the piping system is configured such that feed air is compressed by the main compressor before being divided into the booster feed and the bypass feed.

[0011] In one implementation, the first feed line and the feed bypass share a common section leading to the high-pressure tower. The branch point is located upstream of the shared section on the first feed line.

[0012] In one embodiment, a portion of the pressurized feed, distinct from the first feed, constitutes the second feed. The piping system is configured such that the second feed, after being pressurized by a booster, enters the intermediate position of the high-pressure tower as rising gas. An expander drives the booster.

[0013] In one embodiment, the piping system is configured such that the second feed is pressurized by a booster, cooled by a main heat exchanger, and then enters the high-pressure tower. The piping system is also configured such that the second feed, after being cooled by the main heat exchanger, is depressurized by a pressure-reducing element before entering the intermediate position. The pressure-reducing element is a liquid expander.

[0014] In one embodiment, the piping system includes a branch line that carries a portion of the second feed, after being depressurized by a pressure-reducing element, as a tributary into the low-pressure tower as reflux liquid. The tributary enters the low-pressure tower at the same midpoint as the outlet of the additional piping. The branch line receives cooling through a subcooler, while the additional piping bypasses the subcooler and leads directly to the low-pressure tower.

[0015] In one embodiment, a portion of the pressurized feed that differs from both the first and second feeds constitutes a third feed. The piping system is configured such that the third feed, after being cooled by cooling elements, is fed into the high-pressure tower. The piping system is also configured such that the third feed, after passing through the cooling elements, merges with the second feed, which has expanded after passing through pressure-reducing elements, and together they are fed into the intermediate position of the high-pressure tower.

[0016] In one implementation, the cooling element is a separate heat exchanger from the main heat exchanger. Liquid nitrogen is reheated in the other heat exchanger to provide cooling for the third feed.

[0017] In one embodiment, the piping system is configured such that the extraction point of the branch of the second feed that is fed into the low-pressure tower as reflux liquid is located downstream of the confluence of the third feed and the second feed.

[0018] In one embodiment, the main heat exchanger includes a separate first heat exchanger and a second heat exchanger. Both the first feed and the second feed are cooled via the first heat exchanger, while the bypass feed is cooled via the second heat exchanger.

[0019] The aforementioned air separation unit, by adding auxiliary pipelines, diverts a portion of the initial feed originally intended for the high-pressure tower to the low-pressure tower after expansion and refrigeration. This reduces the heat load on the main condenser-evaporator, allowing for a reduction in its size. Simultaneously, all feed enters the distillation column system for rectification. The throttling effect of the valves in the auxiliary pipelines generates cooling, minimizing or even eliminating any impact on energy consumption or output. Therefore, this air separation unit can meet stringent equipment transport size limitations while minimizing negative impacts on energy consumption or output.

[0020] Furthermore, the aforementioned air separation equipment is particularly suitable for processes where one stream of feed air is pressurized while another is expanded. In particular, the design of the inlet and outlet positions of the additional pipelines helps to optimize distillation efficiency while meeting size constraints. Attached Figure Description

[0021] The advantages and spirit of this utility model can be further understood through the following detailed description and accompanying drawings.

[0022] Figure 1 This is a schematic diagram of an exemplary air separation device according to the present invention. Detailed Implementation

[0023] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. However, it should be understood that this utility model is not limited to the embodiments described below, and the technical concept of this utility model can be implemented in combination with other known technologies or functions, or with other technologies that are the same as those known technologies.

[0024] For example, if the first feature described subsequently in the specification is formed above or on the second feature, this can include embodiments where the first and second features are formed by direct connection, or embodiments where an additional feature is formed between the first and second features, so that the first and second features are not directly connected. Furthermore, when the first element is described in a manner connected or combined with the second element, the description includes embodiments where the first and second elements are directly connected or combined with each other, as well as embodiments where one or more other intervening elements are incorporated to indirectly connect or combine the first and second elements with each other.

[0025] The specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. However, it should be understood that this utility model is not limited to the embodiments described below, and the technical concept of this utility model can be implemented in combination with other known technologies or functions, or with other technologies similar to those known technologies. For example, the first feature described later in the specification being formed above or on the second feature may include an embodiment in which the first and second features are formed by direct connection, or an embodiment in which an additional feature is formed between the first and second features, so that the first and second features are not directly connected. Furthermore, when the first element is described in a manner connected or combined with the second element, the description includes embodiments in which the first and second elements are directly connected or combined with each other, as well as embodiments in which one or more other intervening elements are added to indirectly connect or combine the first and second elements with each other.

[0026] Figure 1 An exemplary diagram illustrates the construction of an air separation unit 10 according to an embodiment of the present invention. The air separation unit 10 includes a piping system 2 and a distillation column system 1. It is understood that the accompanying drawings are merely illustrative and are not necessarily drawn to scale, and should not be construed as limiting the scope of protection actually claimed by the present invention.

[0027] Distillation column system 1 includes a high-pressure column 11 and a low-pressure column 12, which are shown as the lower and upper columns in the diagram, respectively. That is, the operating pressure of the high-pressure column 11 is higher than the operating pressure of the low-pressure column 12. Here, it is only required that one of the two columns has a relatively higher operating pressure and the other a relatively lower operating pressure; the specific pressure range is not limited. For example, the actual pressure of the high-pressure column 11 might be more easily referred to as a medium-pressure column in engineering practice.

[0028] The high-pressure tower 11 and the low-pressure tower 12 are thermally connected via a main condenser-evaporator 13. That is, heat exchange can be achieved between the high-pressure tower 11 and the low-pressure tower 12 through the main condenser-evaporator 13. Specifically, the gas flow at the top of the high-pressure tower 11 condenses into liquid in the main condenser-evaporator 13 and returns to the top of the high-pressure tower 11, while simultaneously heating the liquid flow at the bottom of the low-pressure tower 12, causing it to evaporate into gas flow and rise in the low-pressure tower 12. The main condenser-evaporator 13 can also be called a reboiler, reboiling condenser, etc.

[0029] The piping system 2 includes a first feed line 21. The first feed line 21 is configured such that the first feed a1, after being compressed by the compressor assembly 30, is expanded by the expander 51 and then enters the low position P15 of the high-pressure tower 11 as rising gas.

[0030] It can also be understood that when the text mentions that the piping system is set up to allow the corresponding flow streams to move, it means that the piping system includes the corresponding pipelines, which are shown in the diagrams as lines with arrows indicating the direction of the flow streams. Pipelines, conduits, and pipe segments all refer to the routes for the flow streams and do not limit the physical form of the corresponding components. For example, a pipeline can refer to a segment of a complete pipeline. A pipeline can also be a combination of multiple pipelines connected in sequence. To avoid making the description too lengthy, not every line is represented by a corresponding pipeline, but the lines with arrows in the diagrams can be considered as one or more pipe segments, or one or more pipelines, as needed. In addition, it can be understood that when the text uses terms such as "between," "after," "before," "upstream," "downstream," and similar expressions to describe the arrangement of the flow path, it is with reference to the corresponding flow stream direction.

[0031] Piping system 2 includes an auxiliary pipeline 20. A throttling valve 7 is installed in the auxiliary pipeline 20. The inlet of the auxiliary pipeline 20 is located at the branch point P01 of the first feed pipeline 21 (i.e., the pipeline conveying the first feed a1) between the expander 51 and the high-pressure tower 11. Furthermore, the outlet of the auxiliary pipeline 20 is located at the intermediate position P23 of the low-pressure tower 12 (e.g., ...). Figure 1 (As shown). That is, the additional pipeline 20 introduces the flow stream from the branch point P01 into the low-pressure tower 12.

[0032] It's understandable that when describing a distillation column, using "bottom" and "top" refers to the bottom and top positions of the column, respectively, typically facilitating the extraction of liquid and gas. "Low position" and "high position" indicate that all trays of the column are located above and below that position, respectively, while "middle position" means there are trays both above and below that position, i.e., at least one tray. Describing a position as "equivalent" means the number of trays above (or below) the stream inlet or outlet is the same, while "above" and "below" mean at least one tray difference. Figure 1In the middle, the middle position P14 of the high-pressure tower 11 is higher than the low position P15, the middle position P13 mentioned later is higher than the middle position P14, and the middle position P23 of the low-pressure tower 12 is higher than the middle position P24.

[0033] In the above configuration, compared to existing technologies, a portion of the feed stream originally sent to the high-pressure tower 11, i.e., the first feed a1, is diverted to the low-pressure tower 12, which reduces the load on the main condenser-evaporator 13, thus allowing for a reduction in the size of the main condenser-evaporator 13. Furthermore, the diversion point is located before entering the high-pressure tower 11 and after expansion, and then the pressure is reduced by the throttling valve 7, ensuring both cooling supply and distillation efficiency.

[0034] Figure 1 In this configuration, compressor assembly 30 includes a booster compressor 32. Piping system 2 is configured such that feed air a0 is divided into a booster feed ah, which is pressurized by the booster compressor 32, and a bypass feed ap, which bypasses the booster compressor 32. "Bypass" means not passing through. At least a portion of the booster feed ah constitutes a first feed a1.

[0035] Piping system 2 also includes a feed bypass 29. Feed bypass 29 is configured to allow the bypass feed ap to be cooled by the main heat exchanger 4. Figure 1 After being completely cooled, it also enters the lower P15 of the high-pressure tower 11 as rising gas.

[0036] The first feed pipe 21 is configured to allow the first feed a1 to be cooled after passing through the main heat exchanger 4. Figure 1 After being partially cooled, it enters the expander 51 for expansion.

[0037] Figure 1 In this air separation unit 10, a main compressor 31 is also included. The piping system 2 can be configured such that the feed air a0 is compressed by the main compressor 31 before being split into booster feed ah and bypass feed ap. The main compressor 31 and the booster compressor 32 are commonly referred to in the industry as MAC and BAC.

[0038] like Figure 1 As shown, the first feed line 21 and the feed bypass 29 share a common pipe section 219 leading to the high-pressure tower 11. The branch point P01 is located upstream of the shared pipe section 219 on the first feed line 21. Specifically, the shared pipe section 219 can be a section of pipe near the feed inlet of the high-pressure tower 11. This allows for further optimization of efficiency by drawing the stream before the two streams merge and feeding it into the low-pressure tower 12.

[0039] Figure 1 In the middle, another part of the pressurized feed ah, which is different from the first feed a1, constitutes the second feed a2. The pipeline system 2 is configured such that the second feed a2, after being pressurized by the booster 52, enters the intermediate position P14 of the high-pressure tower 11 as rising gas. Figure 1In this configuration, expander 51 drives turbocharger 52. That is, the expansion work done in expander 51 is at least partially transferred to turbocharger 52, and / or, the work received by turbocharger 52 comes at least partially from expander 51. For example, expander 51 and turbocharger 52 are the expansion and boosting ends of the same turbocharger, respectively. An aftercooler located immediately downstream of turbocharger 52 is also shown in the figure.

[0040] That is, Figure 1 In the illustrated embodiment, one stream of feed air a0 is pressurized by the booster 52, and the other stream is expanded by the expander 51. Both streams ultimately reach different locations on the high-pressure tower 11 as rising air. In another embodiment, one stream of feed air a0 may first enter the booster 52 for pressurization, then expand by the expander 51, and finally reach the high-pressure tower 11 as rising air. For example, the air may also be cooled by the main heat exchanger 4 between pressurization and expansion.

[0041] The term "and / or" as used herein includes any and all combinations of one or more of the related listed items. Unless otherwise stated, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood in the art to which this invention pertains. It should also be understood that terms, such as those defined in common dictionaries, should be understood to have the same meaning as they have in the context of this specification and the related art, and should not be interpreted in an idealized or overly formal sense unless expressly stated herein. For the sake of brevity and / or clarity, well-known functions or constructions may not be described in detail.

[0042] It is also understood that the terms "first" and "second" are used for descriptive purposes only and do not refer to limitations on chronological order, quantity, or importance. They should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated, but are merely used to distinguish one technical feature from another in this technical solution. Therefore, a feature specified with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more (i.e., more than two), unless otherwise explicitly specified. Similarly, qualifiers such as "one" appearing in the text do not refer to limitations on quantity, but rather describe technical features not previously mentioned. Likewise, unless a noun is modified by a specific quantifier, the text should be considered to include both singular and plural forms; the technical solution may include either a singular or plural number of that technical feature. Similarly, modifiers such as "approximately" or "about" preceding numerals in the text usually include the number itself, and their specific meaning should be understood in conjunction with the context.

[0043] Figure 1In the air separation unit 10, the piping system 2 can be configured such that the second feed a2 is pressurized by the booster 52 and then cooled by the main heat exchanger 4. Figure 1 (After being completely cooled) it then enters the high-pressure tower 11 (intermediate position P14). The pipeline system 2 can also be configured such that the second feed a2, after being cooled by the main heat exchanger 4, is depressurized by the pressure reducing element 6 before entering the intermediate position P14. Figure 1 The diagram shows that this line is the second inlet pipe 22. The pressure reducing element 6 is, for example, a liquid expander, such as... Figure 1 As shown.

[0044] Figure 1 In this configuration, the piping system 2 may include a branch pipe 25. The branch pipe 25 carries a portion of the second feed a2 after it has been depressurized by the pressure reducing element 6 as a tributary a25 into the low-pressure tower 12 as reflux liquid. The location where the tributary a25 enters the low-pressure tower 12 is the same as the midpoint P23 of the outlet of the additional piping 20.

[0045] Figure 1 In the middle, the branch pipe 25 can obtain cooling capacity by passing through the subcooler 8, while the auxiliary pipe 20 bypasses the subcooler 8 and goes directly to the low-pressure tower 12.

[0046] Figure 1 In this system, a portion of the pressurized feed ah that differs from both the first feed a1 and the second feed a2 constitutes the third feed a3. The piping system 2 can be configured such that the third feed a3, after being cooled by the cooling element 4m, is fed into the high-pressure tower 11. The piping system 2 can also be configured such that the third feed a3, after passing through the cooling element 4m, merges with the second feed a2, which has expanded after passing through the pressure-reducing element 6, and together they are fed into the intermediate position P14 of the high-pressure tower 11. This further provides cooling capacity.

[0047] like Figure 1 As shown, the cooling element 4m can be another heat exchanger separate from the main heat exchanger 4. Liquid nitrogen ln is reheated by the aforementioned other heat exchanger, which serves as the cooling element 4m, to provide cooling capacity for cooling the third feed a3. For example, liquid nitrogen ln from the backup system is pressurized by a booster pump and then reheated by the aforementioned other heat exchanger, directly serving as the ultra-high pressure nitrogen product N3.

[0048] Figure 1 In the pipeline system 2, the extraction point P5 of the branch a25 of the second feed a2, which is fed into the low-pressure tower 12 as reflux liquid, is located downstream of the confluence point P3 of the third feed a3 and the second feed a2.

[0049] As mentioned earlier, both the booster feed ah and the bypass feed ap are cooled by the main heat exchanger 4 before entering the high-pressure tower 11. Figure 1In this design, the main heat exchanger 4 may include a separate first heat exchanger 41 and a second heat exchanger 42. The first feed a1 and the second feed a2 are both cooled by the first heat exchanger 41, while the bypass feed ap is cooled by the second heat exchanger 42. In practical engineering, the first heat exchanger 41 and the second heat exchanger 42 may be referred to as the high-pressure heat exchanger and the low-pressure heat exchanger, respectively.

[0050] With the above-described configuration, the air separation unit 10 can directly send a portion of the cooled main airflow to the low-pressure tower 12 via an additional pipeline 20 (e.g., reducing the pressure from approximately 5.5 bara to approximately 1.2 bara), thereby reducing the heat load on the main condenser-evaporator 13 and allowing its diameter to meet transportation restrictions. For example, the original diameter of the main condenser-evaporator 13 without the additional pipeline can be reduced by 100 mm, while the additional cooling capacity generated by the throttling reduces the flow rate and power consumption of the booster compressor 32.

[0051] It is understood that when the text describes a stream sequentially entering the first and second elements, or uses similar descriptions, it only indicates the order in which the stream enters the first and second elements, and does not preclude the possibility that the stream passes through a third element between the first and second elements, or that the stream passes through a third element before or after the first element. However, the present invention can be narrowed down to embodiments that only pass through all or part of the illustrated physical elements, as needed. Physical elements include, for example, the compressor (booster), expander, distillation column, evaporator, main heat exchanger, etc., as illustrated, and generally do not include piping elements such as valves or flow meters. In other words, in embodiments, for example, narrowed down to embodiments that only pass through the illustrated physical elements, such piping elements can be provided as needed.

[0052] Figure 1 The direction of each stream in distillation column system 1 is also shown. Figure 1In the process, the oxygen-enriched liquid l1 from the bottom of the high-pressure tower 11 is subcooled by the subcooler 8 and then sent to the intermediate position P24 of the low-pressure tower 12 as reflux liquid. The stream drawn from the intermediate position P13 of the high-pressure tower 11 is subcooled by the subcooler 8 and then sent to the high position P21 of the low-pressure tower 12 as reflux liquid. The stream drawn from the top of the low-pressure tower 12 is divided into two streams, which enter the first heat exchanger 41 and the second heat exchanger 42 respectively for reheating to become sludge nitrogen W1 and sludge nitrogen W2. The stream drawn from the top of the high-pressure tower 11 is reheated by the second heat exchanger 42 to become, for example, medium-pressure nitrogen product N2. Part of the liquid oxygen drawn from the bottom of the main condenser evaporator 13 is subcooled by the subcooler 8 to become liquid oxygen product ol, and part is pressurized by the liquid oxygen pump and then reheated by the first heat exchanger 41 to become nitrogen products O1 and O2. Liquid nitrogen drawn from the high position P11 of the high-pressure tower 11, for example, the collection tank, is subcooled by the subcooler 8 to become liquid nitrogen product nl. The pipelines supplying reflux liquid to the low-pressure column 12 are all equipped with flash valves. It is understood that the distillation column system 1 may also include an argon column, etc., to achieve flow circulation with the low-pressure column 12 and the high-pressure column 11.

[0053] Specifically, the illustrated air separation unit, by adding an additional pipeline downstream of the first heat exchanger, directly feeds a portion of the cooled and expanded first feed, after throttling, into the low-pressure column. By diverting air to the low-pressure column, the distillation process is rebalanced, significantly reducing the heat load on the main condenser-evaporator. This allows the diameter of the main condenser-evaporator to be reduced from, for example, 4.9m to 4.8m, thus overcoming physical limitations. Simultaneously, the throttling process (Joule-Thomson effect) generates additional "self-cooling" in the low-pressure column. This additional cooling capacity reduces reliance on the original main refrigeration, thereby reducing the flow rate and power consumption of the booster compressor, offsetting the impact of the reduced equipment size, and even optimizing energy consumption.

[0054] In summary, the aforementioned air separation equipment fully utilizes distillation potential to meet transportation constraints without significantly impacting output and power consumption. This air separation equipment can be applied to various processes, particularly those with low nitrogen-to-oxygen ratios (N / O), such as N / O <0.5 in argon-producing systems and N / O <0.3 in argon-producing systems.

[0055] Unless otherwise clearly indicated, each aspect or embodiment defined herein may be combined with any other aspect or embodiment. In particular, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous.

[0056] The embodiments described in this specification are merely preferred embodiments of the present invention. These embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. All technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation should be within the scope of the present invention.

Claims

1. An air separation unit, comprising a piping system and a distillation column system, the distillation column system comprising a high-pressure column and a low-pressure column thermally connected by a main condenser-evaporator, the piping system comprising a first feed line, the first feed line being configured such that a first feed, after being compressed by a compressor assembly, is expanded by an expander and then enters the lower part of the high-pressure column as rising gas. Its features are, The piping system includes an auxiliary pipeline equipped with a throttle valve. The inlet of the auxiliary pipeline is located at the branch point of the first feed pipeline between the expander and the high-pressure tower, and the outlet of the auxiliary pipeline is located at the middle position of the low-pressure tower.

2. The air separation equipment as described in claim 1, characterized in that, The compressor assembly includes a booster compressor; The piping system is configured such that the feed air is divided into a pressurized feed that has been pressurized by the pressurized compressor and a bypass feed that bypasses the pressurized compressor, at least a portion of which constitutes the first feed; The pipeline system also includes a feed bypass, which is configured to allow the bypass feed to enter the low position of the high-pressure tower as rising gas after being cooled by the main heat exchanger. The first feed pipeline is configured to allow the first feed to enter the expander for expansion after being cooled by the main heat exchanger. The compressor assembly also includes a main compressor, and the piping system is configured such that the feed air is compressed by the main compressor before being divided into the booster feed and the bypass feed.

3. The air separation equipment as described in claim 2, characterized in that, The first feed line and the feed bypass share a common pipe section leading to the high-pressure tower; The diversion point is located upstream of the shared pipe section on the first feed pipeline.

4. The air separation equipment as described in claim 2, characterized in that, The portion of the pressurized feed that is different from the first feed constitutes the second feed, and the pipeline system is configured such that the second feed is pressurized by the pressurizer and enters the middle position of the high-pressure tower as rising gas. The expander drives the booster.

5. The air separation equipment as described in claim 4, characterized in that, The pipeline system is configured such that the second feed is pressurized by the booster, cooled by the main heat exchanger, and then enters the high-pressure tower. The pipeline system is also configured such that the second feed, after being cooled by the main heat exchanger, is depressurized by the pressure reducing element before entering the intermediate position; The pressure-reducing element is a liquid expander.

6. The air separation equipment as described in claim 5, characterized in that, The pipeline system includes a branch pipeline, which sends a portion of the second feed after being depressurized by the pressure reducing element as a tributary into the low-pressure tower as reflux liquid. The location where the tributary is introduced into the low-pressure tower is the same as the midpoint of the outlet where the additional pipeline is installed; The branch pipeline obtains cooling through a subcooler, while the additional pipeline bypasses the subcooler and leads directly to the low-pressure tower.

7. The air separation equipment as described in claim 5 or 6, characterized in that, The portion of the pressurized feed that is different from both the first feed and the second feed constitutes the third feed, and the pipeline system is configured such that the third feed is cooled by a cooling element before being sent into the high-pressure tower. The piping system is configured such that the third feed, after passing through the cooling element, merges with the second feed, after being expanded by the pressure reducing element, and together they are fed into the intermediate position of the high-pressure tower.

8. The air separation equipment as described in claim 7, characterized in that, The cooling element is another heat exchanger that is separate from the main heat exchanger; The liquid nitrogen is reheated through the other heat exchanger to provide cooling for the third feed.

9. The air separation equipment as described in claim 7, characterized in that, The piping system is configured such that the extraction point of the tributary of the second feed that is fed into the low-pressure tower as reflux liquid is located downstream of the confluence of the third feed and the second feed.

10. The air separation equipment as described in claim 4, characterized in that, The main heat exchanger includes a separate first heat exchanger and a second heat exchanger. Both the first feed and the second feed are cooled by the first heat exchanger, while the bypass feed is cooled by the second heat exchanger.

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