Low-temperature medium refrigerating system with two liquid outlet temperatures

Abstract

The invention relates to a low-temperature medium refrigerating system with two liquid outlet temperatures, which comprises a first temperature zone module and a second temperature zone module, the first temperature zone module comprises a first Stirling cryocooler and a sleeve outer pipe, and the second temperature zone module comprises a second Stirling cryocooler and a sleeve inner pipe; the sleeve inner pipe is sleeved with the sleeve outer pipe, the second Stirling cryocooler is arranged in the sleeve inner pipe and used for refrigerating a second medium in the sleeve inner pipe, and the first Stirling cryocooler is arranged on the outer side of the sleeve inner pipe, located in the sleeve outer pipe and used for refrigerating a first medium between the sleeve inner pipe and the sleeve outer pipe. And the refrigeration temperature of the first medium is higher than that of the second medium. Compared with the prior art, the device has the advantages of simple structure, light equipment, few faults and the like.

Description

Technical Field

[0001] The invention relates to the technical field of low-temperature refrigeration, and in particular to a low-temperature medium refrigeration system with two liquid outlet temperatures. Background Art

[0002] Small refrigeration units are refrigeration equipment for low-temperature cold water or low-temperature media. As a common household appliance, they are widely used in homes, offices and car environments, providing great convenience for people. At present, small refrigeration units usually adopt compression refrigeration cycles, and achieve the refrigeration effect of low-temperature media through core components such as compressors, condensers, expansion valves and evaporators.

[0003] A refrigeration unit as disclosed in CN108351141A includes a first compressor configured and arranged to compress a first refrigerator and a second compressor configured and arranged to compress a second refrigerator. A first condenser of the refrigeration unit is operably coupled to the first compressor, and a second condenser is operably coupled to the second compressor. An evaporator of the refrigeration unit is configured and arranged to flow heat from the first and second refrigerators received from the respective first and second condensers to cool a heat transfer fluid.

[0004] Stirling refrigerators have the advantages of low vibration, compact structure, small size, energy saving and environmental protection, strong reliability, long service life and wide refrigeration temperature range. The Stirling refrigeration principle is based on the reverse Stirling cycle, using the expansion refrigeration of the alternating flow of compressible gas. The theoretical efficiency is the Carnot efficiency. The working fluid inside the system is generally non-polluting inert gas helium. There is no phase change during the operation process, and the sealing method adopts gap sealing. Stirling cryogenic refrigeration units have certain advantages in small cryogenic medium refrigeration equipment, with very few maintenance and failures.

[0005] The above-mentioned small low-temperature medium refrigeration units are still mainly based on compressor refrigeration systems, but compressor refrigeration systems often have many equipment parts, including insulation, medium transmission and other structures, which makes the refrigeration equipment relatively bulky, difficult to carry and install, and has many failures during the operation of the equipment, resulting in high maintenance costs in the later stage. Therefore, it is of great significance to provide a low-temperature medium refrigeration system with stable operation, few failures and simple structure. Summary of the invention

[0006] The purpose of the present invention is to provide a low-temperature medium refrigeration system with two liquid outlet temperatures in order to overcome the defects of the above-mentioned prior art that the small low-temperature medium refrigeration unit is mainly based on a compressor refrigeration system, has many equipment parts, is relatively bulky and prone to failure.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A low-temperature medium refrigeration system with two liquid outlet temperatures, comprising a first temperature zone module and a second temperature zone module, wherein the first temperature zone module comprises a first Stirling refrigerator and a sleeve outer tube, and the second temperature zone module comprises a second Stirling refrigerator and a sleeve inner tube;

[0009] The outer tube of the casing is sleeved on the outside of the inner tube of the casing, the second Stirling refrigerator is arranged inside the inner tube of the casing, and is used to cool the second medium in the inner tube of the casing, the first Stirling refrigerator is arranged outside the inner tube of the casing and inside the outer tube of the casing, and is used to cool the first medium between the inner tube of the casing and the outer tube of the casing, and the cooling temperature of the first medium is higher than the cooling temperature of the second medium.

[0010] Preferably, the first temperature zone module further comprises a dual-refrigeration mechanism cold head fixture, and the second Stirling refrigerator is a dual-refrigeration unit;

[0011] The dual refrigerator cooling head fixture includes an outer pipe joint and an inner pipe joint, both of which are hollow structures. The inner pipe joint is arranged inside the outer pipe joint, the outer pipe of the sleeve connects the two ends of the outer pipe joint, and the inner pipe of the sleeve connects the two ends of the inner pipe joint. The second Stirling refrigerator is fixed on both sides of the outer pipe joint, and the cooling head of the second Stirling refrigerator is located inside the inner pipe joint.

[0012] Preferably, the outer pipe joint and the inner pipe joint are both cubic structures, the dual refrigeration units are symmetrically arranged on both sides of the outer pipe joint, the outer pipe of the sleeve is perpendicular to the setting direction of the dual refrigeration unit, and a channel for the circulation of the first medium is reserved between the inner pipe joint and the outer pipe joint.

[0013] Preferably, an inner tube fin is provided inside the inner tube joint, the inner tube fin is a hollow structure, the inner tube joint is vertically arranged with the inner tube of the sleeve, and the dual refrigeration units are respectively connected to the two ends of the inner tube fin.

[0014] Preferably, the inner tube fin comprises multiple layers of sub-fins, each sub-fin is parallel to each other, each sub-fin is arranged at equal intervals, and the inner tube fin has arc contours on both sides facing the inner tube of the sleeve.

[0015] Preferably, the second temperature zone module also includes a single refrigerator cold head fixture, the single refrigerator cold head fixture includes an outer tube connecting shell of a shell structure, the inner tube of the sleeve passes through the outer tube connecting shell, the inner cavity of the outer tube connecting shell is connected to the outer tube of the sleeve, the first Stirling refrigerator is fixed on the outside of the outer tube connecting shell, and the cooling head of the first Stirling refrigerator is located in the inner cavity of the outer tube connecting shell.

[0016] Preferably, an outer tube fin is provided in the outer tube connecting shell, the cooling head of the first Stirling refrigerator is connected to the outer tube fin, and the outer tube fin includes a first component and a second component symmetrically arranged on both sides of the inner tube of the sleeve, and the first component and the second component are both multi-channel structures.

[0017] Preferably, the first temperature zone module also includes a first low-temperature medium storage tank and a first solution pump. The first low-temperature medium storage tank is provided with a first medium inlet and a first medium outlet. The two ends of the outer tube of the casing are respectively connected to the first low-temperature medium storage tank; the first solution pump is connected to the outer tube of the casing to drive the flow of the medium in the outer tube of the casing.

[0018] Preferably, the second temperature zone module also includes a second low-temperature medium storage tank and a second solution pump, the second low-temperature medium storage tank is provided with a second medium outlet and a second medium inlet, and the two ends of the inner tube of the casing are respectively connected to the second low-temperature medium storage tank; the second solution pump is connected to the inner tube of the casing to drive the flow of the medium in the inner tube of the casing.

[0019] Preferably, the refrigeration temperature difference between the second medium in the inner tube of the casing and the first medium between the outer tube of the casing and the inner tube of the casing is less than 5 degrees Celsius.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] (1) In this scheme, a second medium is transported into the inner tube of the casing, and the second medium is cooled by a second Stirling refrigerator disposed in the inner tube of the casing; a first medium is transported into the outer tube of the casing, and the first medium is cooled by a first Stirling refrigerator disposed between the inner tube of the casing and the outer tube of the casing, thereby realizing refrigeration of two identical or different media, and obtaining two media with set temperatures at the same time.

[0022] By arranging the outer tube of the casing on the outside of the inner tube of the casing, two refrigerant media with different temperatures are transported inside and outside the casing, the second medium in the inner tube of the casing is cooled by the second Stirling refrigerator, and the first medium outside the inner tube of the casing is cooled by the first Stirling refrigerator. The refrigeration system can obtain two media with set temperatures at the same time, and the dual-temperature zone refrigeration system can achieve faster cooling of the two media in the system and improve the refrigeration efficiency. The relatively low-temperature first medium outside the inner tube of the casing can keep the second medium warm, effectively reducing the heat loss in the temperature zone of the inner tube of the casing, improving the refrigeration effect, and reducing the refrigeration energy consumption.

[0023] (2) In this scheme, a corresponding joint is set between the Stirling refrigerator and the casing pipeline, and a fin is set in the joint, so that the cooling head of the Stirling refrigerator is connected to the fin. The corresponding medium flows through the connecting head and contacts the fin, which indirectly expands the contact area between the medium and the cooling head, thereby improving the cooling efficiency and cooling effect of the Stirling refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of the refrigeration unit provided by the present invention;

[0025] Figure 2 A schematic diagram of the structure of a second Stirling refrigerator provided by the present invention;

[0026] Figure 3 A cross-sectional view of the cold head fixture of the dual refrigerator provided by the present invention from a first viewing angle;

[0027] Figure 4 A cross-sectional view of the cold head fixture of the dual refrigerator provided by the present invention from a second viewing angle;

[0028] Figure 5 A cross-sectional view of a cold head fixture of a single refrigerator provided by the present invention;

[0029] Figure 6 A schematic diagram of the structure of the sleeve provided by the present invention;

[0030] In the figure: 1. first low-temperature medium storage tank, 2. first medium inlet, 3. first medium outlet, 4. outer tube of casing, 5. second Stirling refrigerator, 6. cold head fixture of double refrigerator, 7. inner tube of casing, 8. first solution pump, 9. cold head fixture of single refrigerator, 10. first Stirling refrigerator, 11. second medium outlet, 12. second medium inlet, 13. second low-temperature medium storage tank, 14. second solution pump, 15. inner tube fin, 61. outer tube joint, 62. inner tube joint, 91. outer tube connecting shell, 92. outer tube fin. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0034] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0035] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a low-temperature medium refrigeration system with two liquid outlet temperatures, including a first temperature zone module and a second temperature zone module, the first temperature zone module includes a first Stirling refrigerator 10 and a casing outer tube 4, and the second temperature zone module includes a second Stirling refrigerator 5 and a casing inner tube 7;

[0039] The outer tube 4 of the casing is sleeved on the outside of the inner tube 7 of the casing, the second Stirling refrigerator 5 is arranged inside the inner tube 7 of the casing, and is used for cooling the second medium in the inner tube 7 of the casing. The first Stirling refrigerator 10 is arranged outside the inner tube 7 of the casing and inside the outer tube 4 of the casing, and is used for cooling the first medium between the inner tube 7 and the outer tube 4 of the casing. The cooling temperature of the first medium is higher than the cooling temperature of the second medium.

[0040] Working principle: the second medium is transported into the inner tube 7 of the casing, and the second medium is cooled by the second Stirling refrigerator 5 arranged in the inner tube 7 of the casing; the first medium is transported into the outer tube 4 of the casing, and the first medium is cooled by the first Stirling refrigerator 10 arranged between the inner tube 7 of the casing and the outer tube 4 of the casing. The two media are cooled at the same time, so that two identical or different media can be cooled, and two media with set temperatures can be obtained at the same time.

[0041] By sleeve-mounting the outer tube 4 on the outer side of the inner tube 7, the inner side 4 and the outer side of the sleeve transport two refrigerant media of different temperatures, the second medium in the inner tube 7 of the sleeve is refrigerated by the second Stirling refrigerator 5, and the first medium outside the inner tube 7 of the sleeve is refrigerated by the first Stirling refrigerator 10. The refrigeration system can obtain two media of set temperature at the same time, and the dual-temperature zone refrigeration system can achieve faster cooling of the two media of the system, improve the refrigeration efficiency, and the relatively low-temperature first medium outside the inner tube 7 of the sleeve can keep the second medium warm, effectively reduce the heat loss in the temperature zone of the inner tube 7 of the sleeve, improve the refrigeration effect, and reduce the refrigeration energy consumption.

[0042] Preferred implementation mode, as Figures 2 to 4 As shown, the first temperature zone module also includes a dual-refrigeration mechanism cold head fixture 6, and the second Stirling refrigerator 5 is a dual-refrigeration unit;

[0043] The dual refrigerator cooling head fixture 6 includes an outer pipe joint 61 and an inner pipe joint 62. Both the outer pipe joint 61 and the inner pipe joint 62 are hollow structures. The inner pipe joint 62 is arranged inside the outer pipe joint 61. The outer pipe 4 of the sleeve connects the two ends of the outer pipe joint 61, and the inner pipe 7 of the sleeve connects the two ends of the inner pipe joint 62. The second Stirling refrigerator 5 is fixed on both sides of the outer pipe joint 61, and the cooling head of the second Stirling refrigerator 5 is located inside the inner pipe joint 62.

[0044] Among them, the outer pipe joint 61 and the inner pipe joint 62 are both cubic structures, the dual refrigeration units are symmetrically arranged on both sides of the outer pipe joint 61, the sleeve outer pipe 4 is perpendicular to the setting direction of the dual refrigeration unit, and a channel for the circulation of the first medium is reserved between the inner pipe joint 62 and the outer pipe joint 61.

[0045] Furthermore, an inner tube fin 15 is provided inside the inner tube joint 62 . The inner tube fin 15 is a hollow structure. The inner tube joint 62 is vertically arranged with the sleeve inner tube 7 . The dual refrigeration units are respectively connected to the two ends of the inner tube fin 15 .

[0046] Specifically, the inner tube fin 15 includes multiple layers of sub-fins, each sub-fin is parallel to each other, each sub-fin is arranged at equal intervals, and the inner tube fin 15 has arc contours on both sides facing the inner tube 7 of the sleeve.

[0047] A corresponding inner tube joint 62 is arranged between the Stirling refrigerator and the inner tube 7 of the sleeve, and an inner tube fin 15 is arranged in the inner tube joint 62, so that the cooling head of the Stirling refrigerator is connected to the inner tube fin 15, and the second medium in the corresponding inner tube 7 of the sleeve flows through the inner tube joint 62 and contacts the inner tube fin 15, thereby expanding the contact area between the second medium and the cooling head and improving the cooling efficiency and cooling effect of the Stirling refrigerator.

[0048] Preferred implementation mode, as Figure 5 As shown, the second temperature zone module also includes a single refrigerator cold head fixture 9, which includes an outer tube connecting shell 91 of a shell structure, the inner tube 7 of the sleeve passes through the outer tube connecting shell 91, the inner cavity of the outer tube connecting shell 91 is connected to the outer tube 4 of the sleeve, the first Stirling refrigerator 10 is fixed on the outside of the outer tube connecting shell 91, and the cooling head of the first Stirling refrigerator 10 is located in the inner cavity of the outer tube connecting shell 91.

[0049] Among them, an outer tube fin 92 is provided in the outer tube connecting shell 91, and the cooling head of the first Stirling refrigerator 10 is connected to the outer tube fin 92. The outer tube fin 92 includes a first component and a second component symmetrically arranged on both sides of the sleeve inner tube 7, and the first component and the second component are both multi-channel structures.

[0050] The connection structure principle is the same as that of the inner tube 7 of the sleeve and the second Stirling refrigerator 5. An outer tube connecting shell 91 is arranged between the first Stirling refrigerator 10 and the outer tube 4 of the sleeve, and an outer tube fin 92 connected to the refrigeration head of the first Stirling refrigerator 10 is arranged in the outer tube connecting shell 91 to refrigerate the first medium in the outer tube 4 of the sleeve. The holes on the outer tube fin 92 can increase the contact area between the refrigeration head and the first medium, thereby improving the refrigeration effect and refrigeration efficiency.

[0051] Specifically, the first temperature zone module also includes a first low-temperature medium storage tank 1 and a first solution pump 8. The first low-temperature medium storage tank 1 is provided with a first medium inlet 2 and a first medium outlet 3. Both ends of the casing outer tube 4 are respectively connected to the first low-temperature medium storage tank 1; the first solution pump 8 is connected to the casing outer tube 4 to drive the flow of the medium in the casing outer tube 4.

[0052] The second temperature zone module also includes a second low-temperature medium storage tank 13 and a second solution pump 14. The second low-temperature medium storage tank 13 is provided with a second medium outlet 11 and a second medium inlet 12. Both ends of the casing inner tube 7 are respectively connected to the second low-temperature medium storage tank 13; the second solution pump 14 is connected to the casing inner tube 7 to drive the medium flow in the casing inner tube 7.

[0053] The medium inside the first low-temperature medium storage tank 1 and the second low-temperature medium storage tank 13 is a liquid, which can be water, ethylene glycol aqueous solution, ethane, propane and other solutions that need to be cooled. The liquid medium in the low-temperature medium storage tank flows through a solution pump, and is cooled during the flow process. After cooling, it is transported back to the storage tank, and two media with set temperatures can be obtained after a period of circulation. The refrigerated medium can also be passed through a specific area to cool the specific area.

[0054] like Figure 6 As shown, the refrigeration temperature difference between the second medium in the inner tube 7 of the casing and the first medium between the outer tube 4 of the casing and the inner tube 7 of the casing is less than 5 degrees Celsius. The difference in the command temperature of the two media is limited. If the difference between the two is large, the refrigeration effect of the two media will be affected. When the temperature difference is controlled within a certain range, the medium circulating in the outer layer can have a heat preservation effect on the lower temperature medium in the tube.

[0055] The outer side of the outer tube 4 of the sleeve is provided with a corresponding insulation structure, which is a conventional technical means, so it will not be repeated; compared with preparing two solutions with set temperatures, two sets of refrigeration equipment are set up separately, the required pipeline materials and insulation materials simplify the structure of the equipment and reduce the cost of the equipment. The volume of the small-capacity low-temperature medium refrigerator is reduced, the equipment is light, and it is more convenient to carry or assemble and disassemble.

[0056] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A low-temperature medium refrigeration system with two liquid outlet temperatures, characterized in that: It comprises a first temperature zone module and a second temperature zone module, wherein the first temperature zone module comprises a first Stirling refrigerator (10) and a casing outer tube (4), and the second temperature zone module comprises a second Stirling refrigerator (5) and a casing inner tube (7); The outer casing tube (4) is sleeved on the outside of the inner casing tube (7); the second Stirling refrigerator (5) is arranged inside the inner casing tube (7) and is used to refrigerate a second medium in the inner casing tube (7); the first Stirling refrigerator (10) is arranged outside the inner casing tube (7) and inside the outer casing tube (4) and is used to refrigerate a first medium between the inner casing tube (7) and the outer casing tube (4); and the refrigeration temperature of the first medium is higher than the refrigeration temperature of the second medium.

2. A low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 1, characterized in that: The first temperature zone module further comprises a dual-refrigeration machine cold head fixture (6), and the second Stirling refrigerator (5) is a dual-refrigeration machine set; The dual refrigerator cold head fixture (6) comprises an outer pipe joint (61) and an inner pipe joint (62), both of which are hollow structures, and the inner pipe joint (62) is arranged inside the outer pipe joint (61), the outer pipe of the sleeve (4) is connected to the two ends of the outer pipe joint (61), and the inner pipe of the sleeve (7) is connected to the two ends of the inner pipe joint (62), the second Stirling refrigerator (5) is fixed on both sides of the outer pipe joint (61), and the cold head of the second Stirling refrigerator (5) is located inside the inner pipe joint (62).

3. A low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 2, characterized in that: The outer pipe joint (61) and the inner pipe joint (62) are both cubic structures, the dual refrigeration units are symmetrically arranged on both sides of the outer pipe joint (61), the sleeve outer pipe (4) and the dual refrigeration unit are arranged perpendicular to each other, and a channel for the circulation of a first medium is reserved between the inner pipe joint (62) and the outer pipe joint (61).

4. A low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 2, characterized in that: An inner tube fin (15) is provided inside the inner tube joint (62), and the inner tube fin (15) is a hollow structure. The inner tube joint (62) is vertically arranged with the sleeve inner tube (7), and the dual refrigeration unit is respectively connected to the two ends of the inner tube fin (15).

5. A low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 4, characterized in that: The inner tube fin (15) comprises multiple layers of sub-fins, each sub-fin is parallel to each other and is arranged at equal intervals. The inner tube fin (15) has arc contours on both sides facing the inner tube (7) of the sleeve.

6. The low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 1, characterized in that: The second temperature zone module further comprises a single refrigerator cold head fixture (9), the single refrigerator cold head fixture (9) comprising an outer tube connection shell (91) of a shell structure, the sleeve inner tube (7) passes through the outer tube connection shell (91), the inner cavity of the outer tube connection shell (91) is connected to the sleeve outer tube (4), the first Stirling refrigerator (10) is fixed on the outside of the outer tube connection shell (91), and the cold head of the first Stirling refrigerator (10) is located in the inner cavity of the outer tube connection shell (91).

7. A low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 6, characterized in that: An outer tube fin (92) is arranged in the outer tube connection shell (91), and the cooling head of the first Stirling refrigerator (10) is connected to the outer tube fin (92). The outer tube fin (92) comprises a first component and a second component symmetrically arranged on both sides of the sleeve inner tube (7), and the first component and the second component are both multi-channel structures.

8. The low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 1, characterized in that: The first temperature zone module further comprises a first low-temperature medium storage tank (1) and a first solution pump (8); the first low-temperature medium storage tank (1) is provided with a first medium inlet (2) and a first medium outlet (3); both ends of the casing outer tube (4) are respectively connected to the first low-temperature medium storage tank (1); the first solution pump (8) is connected to the casing outer tube (4) and is used to drive the medium in the casing outer tube (4) to flow.

9. The low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 1, characterized in that: The second temperature zone module further comprises a second low-temperature medium storage tank (13) and a second solution pump (14); the second low-temperature medium storage tank (13) is provided with a second medium outlet (11) and a second medium inlet (12); both ends of the casing inner tube (7) are respectively connected to the second low-temperature medium storage tank (13); the second solution pump (14) is connected to the casing inner tube (7) to drive the medium in the casing inner tube (7) to flow.

10. The low-temperature medium refrigeration system with two liquid outlet temperatures according to claim 1, characterized in that: The refrigeration temperature difference between the second medium in the sleeve inner tube (7) and the first medium between the sleeve outer tube (4) and the sleeve inner tube (7) is less than 5 degrees Celsius.

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