Low-pressure liquid oxygen cold energy recovery device in a client

Abstract

The utility model discloses a kind of client medium-low pressure liquid oxygen cold quantity recovery device.The device includes air compressor, air cold dryer, air drying purifier, cold quantity recovery liquefied cold box and liquid air storage tank, wherein cold quantity recovery liquefied cold box includes main heat exchanger, supercooler and condensation evaporator.By the atmospheric air after compression, cooling, purification enters cold quantity recovery liquefied cold box, using medium-low pressure liquid oxygen provides cold quantity liquefied air in condensation evaporator, and part is stored as liquid air product after supercooling by supercooler, part is returned to supercooler or main heat exchanger reheating by throttling, for regenerating purifier or as atmospheric air output.The utility model effectively recovers the cold quantity in liquid oxygen gasification process, produces liquid air product, realizes energy saving and environmental protection.

Description

Technical Field

[0001] This utility model belongs to the field of liquid oxygen cold energy recovery technology, and relates to a low-pressure liquid oxygen cold energy recovery device for client applications. Background Technology

[0002] Liquid oxygen is the liquid form of oxygen and an important substance widely used in industry, science and technology, and medicine. It is widely applied in metallurgy, chemical engineering, glass manufacturing, electronics manufacturing, food preservation, and high-efficiency combustion. Liquid oxygen is a light blue liquid with strong paramagnetism. With its wide range of industrial and medical applications, liquid oxygen has a high total expansion ratio of 800:1, making it more economical to transport than gases, which is why it is widely used in modern industrial production. With the rapid modernization of my country, the application of oxygen is becoming increasingly widespread. Besides metallurgy and chemical engineering, liquid oxygen users are showing a trend towards smaller and more dispersed volumes. The core of gas liquefaction is to reduce the distance between gas molecules by lowering the temperature and increasing the pressure, thus achieving a liquefied state. The development of low-temperature physics in the late 19th century provided theoretical support for oxygen liquefaction. Liquid oxygen is usually stored and transported in liquid form, and when used at the user's end, it needs to be converted into gaseous oxygen through a vaporization process to supply the user's pipeline network. However, the vaporization process of liquid oxygen releases a large amount of cold energy, which, if not recovered and utilized, will be directly discharged into the environment, leading to energy waste and environmental thermal pollution. According to relevant statistics, global annual liquid oxygen production exceeds hundreds of millions of tons. A significant proportion of this energy consumption is due to cooling losses during the vaporization process, particularly in low- and medium-pressure liquid oxygen applications (approximately 0.2-0.4 MPa). In industrial production, liquid oxygen is typically vaporized using ambient air vaporizers. During this process, a large amount of cooling energy is directly carried away by the air and not effectively utilized, representing a significant waste for businesses. Cooling energy recovery addresses this by recycling the cooling energy released during liquid oxygen vaporization to produce liquid air, thereby reducing operating costs for businesses.

[0003] In existing technologies, the recovery of liquid oxygen cold energy mainly relies on traditional air separation devices or simple heat exchange systems. For example, the traditional cryogenic air separation (ASU) method achieves air liquefaction through multi-stage compression and expansion, but such devices are bulky, energy-intensive, and unsuitable for small-scale client applications. Some technical literature proposes systems that utilize liquid oxygen cold energy to pre-cool air, but these systems are often limited to the production of high-purity oxygen and cannot effectively handle the recovery of cold energy from medium- and low-pressure liquid oxygen, with low recovery efficiency, recovering only 30%-50% of the cold energy. Furthermore, in existing recovery devices, air pretreatment stages (such as drying and purification) are often independent of the cold energy recovery system, resulting in a complex overall process and high equipment investment. Existing cold energy recovery technologies are mainly for large-scale cold energy recovery and are relatively mature. However, for decentralized, small-scale cold energy recovery, implementation is more difficult, and there are currently no mature devices available. Utility Model Content

[0004] In view of this, the purpose of this utility model is to solve the problem of cold energy recovery and utilization of liquid oxygen vaporization by decentralized users, and to provide a low-pressure liquid oxygen cold energy recovery device for client-side applications. By optimizing the device structure and process flow, the cold energy of liquid oxygen is effectively recovered to generate liquid air products, while reducing overall energy consumption.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A client-side low-pressure liquid oxygen cold energy recovery device includes an air compressor, an air dryer, an air dryer and purifier, a cold energy recovery liquefaction cold box, and a liquid air storage tank; the cold energy recovery liquefaction cold box includes a main heat exchanger, a subcooler, and a condenser-evaporator; The air compressor has one set of inlets and outlets, namely an air inlet and an air outlet; the air dryer has two sets of inlets and outlets and a condensate drain outlet, namely the air inlet and air outlet of the dryer, and the refrigerant inlet and refrigerant outlet of the dryer; the air dryer purifier has two sets of inlets and outlets, namely the purifier air inlet and purifier air outlet, and the desorbed gas inlet and desorbed gas outlet. The main heat exchanger is provided with at least three sets of inlets and outlets, namely a first heat exchange inlet and a first heat exchange outlet, a second heat exchange inlet and a second heat exchange outlet, and a third heat exchange inlet and a third heat exchange outlet; the subcooler is provided with two sets of inlets and outlets, namely a first subcooling inlet and a first subcooling outlet, and a second subcooling inlet and a second subcooling outlet; the condenser-evaporator is provided with two sets of inlets and outlets and a waste liquid discharge port, namely a first condenser-evaporator inlet and a first condenser-evaporator outlet, and a second condenser-evaporator inlet and a second condenser-evaporator outlet; the liquid air storage tank is provided with one set of inlets and outlets, namely a liquid air inlet and a liquid air vapor outlet; The air compressor has an air inlet connected to the atmosphere and an air outlet connected to the air inlet of the refrigerated dryer. It is used to compress atmospheric air and send it to the refrigerated dryer for cooling and dehydration. The air outlet of the refrigerated dryer is connected to the air inlet of the purifier. It is used to send the cooled air to the air drying purifier for purification and removal of impurities. The air outlet of the purifier is connected to the first heat exchange inlet. It is used to send the purified air into the main heat exchanger for cooling. The first heat exchange outlet is connected to the first inlet of the condenser-evaporator, used to send cooled air into the condenser-evaporator for liquefaction; the first outlet of the condenser-evaporator is connected to the first subcooling inlet, used to send liquefied air into the subcooler for subcooling; the first subcooling outlet is divided into at least two flow paths: the first path is connected to the liquid air inlet, used to store liquid air products; the second path, after being depressurized and cooled by a throttling valve, is connected to the second subcooling inlet, serving as a cold source for the subcooler to provide subcooling capacity; the second subcooling outlet is connected to the second heat exchange inlet, used to send reheated gas into the main heat exchanger for further reheating; the second heat exchange outlet is connected to the desorbed gas inlet, used to send the reheated gas as desorbed gas into the air dryer-purifier for regeneration, and the air after the desorbed gas outlet is vented. The second inlet of the condenser-evaporator is connected to a liquid oxygen storage tank to receive medium- and low-pressure liquid oxygen; the second outlet of the condenser-evaporator is connected to the third inlet of the heat exchanger to send the vaporized oxygen into the main heat exchanger for further reheating; the third outlet of the heat exchanger is connected to the user-end oxygen pipeline network to output reheated oxygen.

[0006] Furthermore, the main heat exchanger is also provided with a fourth heat exchange inlet and a fourth heat exchange outlet; the first subcooled outlet is divided into three paths, of which the third path is connected to the fourth heat exchange inlet after being depressurized and cooled by a throttling valve, and is used to directly send the throttled liquid air into the main heat exchanger for reheating as atmospheric pressure air output; the fourth heat exchange outlet is connected in parallel with the second heat exchange outlet to the desorbed gas inlet, and is used to merge into desorbed gas.

[0007] Furthermore, the air compressor, air dryer, air dryer purifier, cold energy recovery liquefaction box, and liquid air storage tank are all integrated on the skid-mounted module.

[0008] Furthermore, the liquid air vapor outlet is connected to the subcooled second outlet or the heat exchange second inlet, for reusing the evaporated vapor into the reheating path.

[0009] Furthermore, the waste liquid discharge port is located at the bottom of the condenser-evaporator to prevent the accumulation of hydrocarbons in the liquid oxygen.

[0010] The beneficial effects of this utility model are as follows: This utility model provides a low-pressure liquid oxygen cooling recovery device for client applications, which has significant advantages over existing technologies.

[0011] Firstly, by integrating an air compressor, a refrigerated dryer, a drying and purifying unit, and a cold energy recovery liquefaction box, the cascade utilization of liquid oxygen's cooling capacity is achieved. In traditional methods, the cooling capacity of liquid oxygen is often directly lost during vaporization. However, this invention utilizes a condenser-evaporator to directly transfer the cooling capacity of liquid oxygen to the air, achieving highly efficient air liquefaction with a recovery rate of over 80%. Compared to traditional vaporization processes, this saves refrigeration energy equivalent to the liquid air production, resulting in a reduction of thousands of tons of carbon emissions annually.

[0012] Secondly, this invention reduces system energy consumption. The air compressor uses a single-stage oil-free, water-lubricated screw compressor, requiring only pressurization to 0.7-0.8 MPa, far lower than the 3 MPa or higher compression requirement of traditional air liquefaction, reducing power consumption by more than 50%. Simultaneously, the introduction of a subcooler ensures lower liquid air product temperatures, reducing evaporation losses in the storage tank and improving product stability.

[0013] Third, from an environmental perspective, this invention significantly reduces energy waste and pollution. The recovery of the cooling energy from liquid oxygen combustion is equivalent to indirectly reducing fossil fuel use, aligning with global sustainable development goals. Simultaneously, the waste liquid discharge port design ensures system safety, preventing overpressure or impurity accumulation.

[0014] Fourth, this invention improves operational reliability and safety. The oil-free water-lubricated compressor avoids oil contamination, the refrigerated dryer effectively removes water and prevents ice blockage, and the purifier removes trace amounts of moisture, CO2, hydrocarbons, and other impurities, ensuring stable operation of the cryogenic equipment and the safety of subsequent liquid air utilization in the air separation unit. The integrated cold box design reduces piping connections and lowers the risk of leakage.

[0015] Overall, this invention not only solves the technical problem but also provides a scalable solution applicable to various industrial clients, thus promoting the advancement of gas recovery technology.

[0016] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the low-pressure liquid oxygen cooling recovery device in the client-side of Embodiment 1 of this utility model.

[0018] Figure 2This is a schematic diagram of the low-pressure liquid oxygen cooling recovery device in the client-side of Embodiment 2 of this utility model.

[0019] Figure labels: 1-Air compressor; 2-Air refrigerated dryer; 3-Air drying and purifying unit; 4-Main heat exchanger; 5-Subcooler; 6-Liquid air storage tank; 7-Condenser-evaporator; 11-Air inlet; 12-Air outlet; 21-Air inlet; 22-Air outlet; 23-Refrigerant circulation inlet; 24-Refrigerant circulation outlet; 31-Air drying and purifying unit inlet; 32-Air drying and purifying unit outlet; 33-Desorbed gas inlet; 34-Desorbed gas outlet; 41-First heat exchanger inlet; 42-First heat exchanger outlet; 43 44-Heat exchanger second inlet; 45-Heat exchanger second outlet; 46-Heat exchanger third inlet; 47-Heat exchanger fourth inlet; 48-Heat exchanger fourth outlet; 51-Subcooling first inlet; 52-Subcooling first outlet; 53-Subcooling second inlet; 54-Subcooling second outlet; 61-Liquid air inlet; 62-Liquid air vapor outlet; 71-Condenser evaporator second inlet; 72-Condenser evaporator second outlet; 73-Waste liquid discharge port; 74-Condenser evaporator first inlet; 75-Condenser evaporator first inlet. Detailed Implementation

[0020] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0021] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0022] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0023] Example 1 Please see Figure 1 A device for recovering cold energy from low-pressure liquid oxygen in a client application includes an air compressor 1, an air dryer 2, an air dryer and purifier 3, a cold energy recovery liquefaction box, and a liquid air storage tank 6; the cold energy recovery liquefaction box includes a main heat exchanger 4, a subcooler 5, and a condenser-evaporator 7. Air compressor 1 is an oil-free, water-lubricated air compressor, equipped with an air inlet 11 and an air outlet 12. Air dryer 2 has five inlets and outlets: air inlet 21, air outlet 22, refrigerant circulation inlet 23, refrigerant circulation outlet 24, and condensate drain 25. Air dryer / purifier 3 has two sets of inlets and outlets: air inlet 31, air outlet 32, and desorbed gas inlet 33 and desorbed gas outlet 34. Main heat exchanger 4 has three sets of inlets and outlets: first heat exchange inlet 41, first heat exchange outlet 42, and second heat exchange outlet 44. The heat exchanger has an inlet 43, a second heat exchange outlet 44, a third heat exchange inlet 45, and a third heat exchange outlet 46; the subcooler 5 has two sets of inlets and outlets, namely a first subcooling inlet 51, a first subcooling outlet 52, a second subcooling inlet 53, and a second subcooling outlet 54; the liquid air storage tank 6 has one set of inlets and outlets, namely a liquid air inlet 61 and a liquid air vapor outlet 62; the condenser evaporator 7 has five inlets and outlets, namely a first condenser evaporator inlet 74, a first condenser evaporator outlet 75, a second condenser evaporator inlet 71, a second condenser evaporator outlet 72, and a waste liquid discharge outlet 73.

[0024] Air comes from the atmosphere and enters through the air inlet 11 of the air compressor 1. The air outlet 12 is connected to the air inlet 21 of the refrigerated dryer. The generated condensate is discharged through the condensate drain 25. The air outlet 22 of the refrigerated dryer is connected to the air inlet 31 of the purifier. The air outlet 32 ​​of the purifier is connected to the first heat exchange inlet 41, the first heat exchange outlet 42 is connected to the first inlet 74 of the condenser-evaporator, the first outlet 75 of the condenser-evaporator is connected to the first inlet 51 of the subcooler, the first outlet 52 of the subcooler is split into two paths: one path is connected to the second inlet 53 of the subcooler via a throttling valve; the other path is connected to the liquid air inlet 61 of the liquid air storage tank; the second outlet 54 of the subcooler is connected to the second inlet 43 of the heat exchanger; the second outlet 44 of the heat exchanger is connected to the desorbed gas inlet 33; the liquid air vapor outlet 62 of the liquid air storage tank is connected to the second outlet 54 of the subcooler; the second inlet 71 of the condenser-evaporator is connected to the liquid air inlet 61 of the liquid air storage tank; the second outlet 72 of the condenser-evaporator is connected to the third inlet 45 of the heat exchanger; the third outlet 46 of the heat exchanger is connected to the user's oxygen pipeline network; part of the liquid oxygen is discharged through the waste liquid discharge outlet 73.

[0025] Among them, air compressor 1 is a single-stage compression oil-free water-lubricated screw compressor.

[0026] A method for recovering cold energy from low-pressure liquid oxygen in a client-side application involves using the aforementioned apparatus. Air is pressurized by an air compressor 1 and then cooled by an air dryer 2. It is then purified in an air dryer purifier 3 and then enters the main heat exchanger 4 in the cold energy recovery liquefaction cold box. The air is liquefied in a condenser evaporator 7 and then subcooled by a cooler 5. Liquid oxygen from a liquid oxygen storage tank 6, pressurized by a liquid oxygen pump, enters the condenser evaporator 7 to provide cooling energy, then enters the main heat exchanger 4 in the cold energy recovery liquefaction cold box for reheating, and finally enters the user's oxygen pipeline network. Air is pressurized to 0.7 MPa by air compressor 1, with an interface pipe diameter of DN80. Liquid oxygen is drawn from the user's liquid oxygen pump and sent to the liquid oxygen inlet 71 of the condenser / evaporator 7 in the cold energy recovery liquefaction cold box, with a junction pressure of approximately 0.4 MPa and an interface pipe diameter of DN40. Atmospheric pressure air is drawn from the liquid oxygen cold energy recovery liquefaction cold box and sent to the air dryer / purifier 3, with a junction pressure of approximately 10 kPa and an interface pipe diameter of DN40. Liquid air is drawn from the cold energy recovery liquefaction cold box and sent to the liquid air storage tank 6, with a junction pressure of approximately 0.2 MPa and an interface pipe diameter of DN25. Oxygen is drawn from the cold energy recovery liquefaction cold box and sent to the user's main oxygen pipe, with a junction pressure of approximately 0.2 MPa and an interface pipe diameter of DN80.

[0027] The raw material used in this invention is liquid oxygen: 1000 Nm³. 3 / h (converted to gaseous state), 0.2MPa; Air: 1150Nm 3 / h, 3.0MPa. Product obtained: Liquid air: 480Nm 3 / h (converted to gaseous state); Normal pressure air: 600 Nm3 / h, 98kPa; Oxygen: 500Nm 3 / h, 0.4MPa.

[0028] Example 2 Please see Figure 2 A device for recovering cold energy from low-pressure liquid oxygen in a client application includes an air compressor 1, an air dryer 2, an air dryer and purifier 3, a cold energy recovery liquefaction box, and a liquid air storage tank 6; the cold energy recovery liquefaction box includes a main heat exchanger 4, a subcooler 5, and a condenser-evaporator 7. Air compressor 1 is an oil-free, water-lubricated air compressor, and is equipped with an air inlet 11 and an air outlet 12. Air dryer 2 has five inlets and outlets: air inlet 21, air outlet 22, refrigerant circulation inlet 23, refrigerant circulation outlet 24, and condensate drain 25. Air dryer / purifier 3 has two sets of inlets and outlets: air inlet 31, air outlet 32, desorbed gas inlet 33, and desorbed gas outlet 34. Main heat exchanger 4 has four sets of inlets and outlets: first heat exchange inlet 41, first heat exchange outlet 42, second heat exchange inlet 43, and second heat exchange outlet 44. The heat exchanger has an outlet 44, a third heat exchange inlet 45, a third heat exchange outlet 46, a fourth heat exchange inlet 47, and a fourth heat exchange outlet 48; the subcooler 5 has two sets of inlets and outlets, namely a first subcooling inlet 51, a first subcooling outlet 52, a second subcooling inlet 53, and a second subcooling outlet 54; the liquid air storage tank 6 has one set of inlets and outlets, namely a liquid air inlet 61 and a liquid air vapor outlet 62; the condenser evaporator 7 has five inlets and outlets, namely a first condenser evaporator inlet 74, a first condenser evaporator outlet 75, a second condenser evaporator inlet 71, a second condenser evaporator outlet 72, and a waste liquid discharge outlet 73.

[0029] The raw material air comes from the atmosphere and enters through the air inlet 11 of the air compressor. The air outlet 12 of the air compressor is connected to the air inlet 21 of the refrigerated dryer. The generated condensate is discharged through the condensate drain 25. The air outlet 22 of the refrigerated dryer is connected to the air inlet 31 of the purifier. The air outlet 32 ​​of the purifier is connected to the first heat exchange inlet 41. The first heat exchange outlet 42 is connected to the first inlet 74 of the condenser-evaporator. The first outlet 75 of the condenser-evaporator is connected to the first inlet 51 of the subcooler. The first outlet 52 of the subcooler is divided into three paths: one path is connected to the second inlet 53 of the subcooler via a throttling valve; one path is connected to the third heat exchange inlet 45 via a throttling valve; and one path is connected to the liquid air inlet 61 of the liquid air storage tank. The second outlet 54 of the subcooler is connected to the second inlet 43 of the heat exchanger. The liquid air vapor outlet 62 of the liquid air storage tank is connected to the second outlet 54 of the subcooler. The second outlet 44 and the third outlet 46 of the heat exchanger are connected in parallel to the desorbed gas inlet 33. The second inlet 71 of the condenser-evaporator is connected to the liquid oxygen storage tank. The second outlet 72 of the condenser-evaporator is connected to the fourth inlet 47 of the heat exchanger. The fourth outlet 48 of the heat exchanger is connected to the user's oxygen pipeline network. Part of the liquid oxygen is discharged through the waste liquid discharge outlet 73.

[0030] Among them, air compressor 1 is a single-stage compression oil-free water-lubricated screw compressor.

[0031] A method for recovering cold energy from low-pressure liquid oxygen in a client-side application involves using the aforementioned apparatus. Air is pressurized by an air compressor, cooled by a refrigerated dryer, purified in an air dryer, and then enters the main heat exchanger in a cold energy recovery liquefaction cold box. The air is then liquefied in a condenser-evaporator and subcooled by a cooler. Liquid oxygen from a liquid oxygen storage tank, pressurized by a liquid oxygen pump, enters the condenser-evaporator to provide cooling, then reheats in the main heat exchanger of the cold energy recovery liquefaction cold box, and finally enters the user's oxygen pipeline network. The supercooled liquid air is divided into three destinations. One part is throttled to atmospheric pressure and returned to the subcooler, where it is vaporized and reheated before entering the main heat exchanger for further reheating. Then, it merges with the gas reheated by the main heat exchanger from the liquid air storage tank and enters the air dryer and purifier as desorption gas. Another part is throttled to atmospheric pressure and directly enters the main heat exchanger for reheating, then merges with the atmospheric pressure air after the main heat exchanger. The majority of the remainder is sent to the liquid air storage tank as liquid air product.

[0032] Air is pressurized to 0.78 MPa by air compressor 1, with a DN50 interface pipe. Liquid oxygen is drawn from the user's liquid oxygen pump and sent to the cold energy recovery liquefaction tank, with a connection point pressure of approximately 0.21 MPa and a DN25 interface pipe. Atmospheric pressure air is drawn from the liquid oxygen cold energy recovery liquefaction tank and sent to the air dryer purifier 3, with a connection point pressure of approximately 15 kPa and a DN50 interface pipe. Liquid air is drawn from the cold energy recovery liquefaction tank and sent to the liquid air storage tank 6, with a connection point pressure of approximately 0.2 MPa and a DN25 interface pipe. Oxygen is drawn from the cold energy recovery liquefaction tank and sent to the user's main oxygen pipe, with a connection point pressure of approximately 0.2 MPa and a DN50 interface pipe.

[0033] The raw material used in this invention is liquid oxygen: 500 Nm³. 3 / h (converted to gaseous state), 0.21MPa; Air: 650Nm 3 / h, 0.78MPa. Product obtained: Liquid air: 515Nm 3 / h (converted to gaseous state); Normal pressure air: 145Nm 3 / h, 98kPa; Oxygen: 498Nm 3 / h, 0.2MPa.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A low-pressure liquid oxygen cooling capacity recovery device for client applications, characterized in that, It includes an air compressor, an air dryer, an air dryer and purifier, a cold energy recovery liquefaction box, and a liquid air storage tank; the cold energy recovery liquefaction box includes a main heat exchanger, a subcooler, and a condenser-evaporator; The air compressor has one set of inlets and outlets, namely an air inlet and an air outlet; the air dryer has two sets of inlets and outlets and a condensate drain outlet, namely the air inlet and air outlet of the dryer, and the refrigerant inlet and refrigerant outlet of the dryer; the air dryer purifier has two sets of inlets and outlets, namely the purifier air inlet and purifier air outlet, and the desorbed gas inlet and desorbed gas outlet. The main heat exchanger is provided with at least three sets of inlets and outlets, namely a first heat exchange inlet and a first heat exchange outlet, a second heat exchange inlet and a second heat exchange outlet, and a third heat exchange inlet and a third heat exchange outlet; the subcooler is provided with two sets of inlets and outlets, namely a first subcooling inlet and a first subcooling outlet, and a second subcooling inlet and a second subcooling outlet; the condenser-evaporator is provided with two sets of inlets and outlets and a waste liquid discharge port, namely a first condenser-evaporator inlet and a first condenser-evaporator outlet, and a second condenser-evaporator inlet and a second condenser-evaporator outlet; the liquid air storage tank is provided with one set of inlets and outlets, namely a liquid air inlet and a liquid air vapor outlet; The air compressor has an air inlet connected to the atmosphere and an air outlet connected to the air inlet of the refrigerated dryer. It is used to compress atmospheric air and send it to the refrigerated dryer for cooling and dehydration. The air outlet of the refrigerated dryer is connected to the air inlet of the purifier. It is used to send the cooled air to the air drying purifier for purification and removal of impurities. The air outlet of the purifier is connected to the first heat exchange inlet. It is used to send the purified air into the main heat exchanger for cooling. The first heat exchange outlet is connected to the first inlet of the condenser-evaporator and is used to send cooled air into the condenser-evaporator for liquefaction; the first outlet of the condenser-evaporator is connected to the first subcooling inlet and is used to send liquefied air into the subcooler for subcooling; the first subcooling outlet is divided into at least two flow paths: the first path is connected to the liquid air inlet and is used to store liquid air products. The second path, after being depressurized and cooled by a throttling valve, is connected to the second subcooling inlet, serving as a cold source for the subcooler to provide subcooling capacity; the second subcooling outlet is connected to the second heat exchange inlet, used to send the reheated gas into the main heat exchanger for further reheating; the second heat exchange outlet is connected to the desorption gas inlet, used to send the reheated gas as desorption gas into the air dryer purifier for regeneration; and the air after the desorption gas outlet is vented. The second inlet of the condenser-evaporator is connected to a liquid oxygen storage tank to receive medium- and low-pressure liquid oxygen; the second outlet of the condenser-evaporator is connected to the third inlet of the heat exchanger to send the vaporized oxygen into the main heat exchanger for further reheating; the third outlet of the heat exchanger is connected to the user-end oxygen pipeline network to output reheated oxygen.

2. The client-side low-pressure liquid oxygen cooling recovery device according to claim 1, characterized in that: The main heat exchanger is also provided with a fourth heat exchange inlet and a fourth heat exchange outlet; the first subcooled outlet is divided into three paths, of which the third path is connected to the fourth heat exchange inlet after being depressurized and cooled by a throttling valve, and is used to directly send the throttled liquid air into the main heat exchanger for reheating as atmospheric pressure air output; the fourth heat exchange outlet is connected to the desorption gas inlet in parallel with the second heat exchange outlet, and is used to merge into desorption gas.

3. The low-pressure liquid oxygen cooling recovery device for the client as described in claim 1, characterized in that: The air compressor, air dryer, air dryer purifier, cold energy recovery liquefaction box, and liquid air storage tank are all integrated on the skid-mounted module.

4. The low-pressure liquid oxygen cooling recovery device for the client as described in claim 1, characterized in that: The liquid air vapor outlet is connected to the subcooled second outlet or the heat exchange second inlet, and is used to reuse the evaporated vapor in the reheating path.

5. The client-side low-pressure liquid oxygen cooling recovery device according to claim 1, characterized in that: The waste liquid discharge port is located at the bottom of the condenser-evaporator to prevent the accumulation of hydrocarbons in the liquid oxygen.

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