Ultralow-temperature refrigeration system

Abstract

The utility model relates to an ultralow temperature refrigerating system, which comprises a first-stage refrigerating system and a second-stage refrigerating system, the first-stage refrigerating system and the second-stage refrigerating system are respectively provided with a first-stage heat exchange tube and a second-stage heat exchange tube, the outer sides of the two heat exchange tubes are sleeved with heat conduction materials, and the outer sides of the heat conduction materials are sleeved with heat insulation sleeves. The first heat exchange surface of the first-stage heat exchange tube and the second heat exchange surface of the second-stage heat exchange tube are concave-convex complementary wavy curved surfaces and are in direct contact for heat exchange, so that the heat exchange area is large, and the heat exchange efficiency is high; the outer surface of the heat exchange tube is in indirect contact with the outer surface of the secondary heat exchange tube through a heat conduction material for indirect heat exchange; the axial grooves and the axial protrusions are arranged on the inner pipe walls of the heat exchange pipes, the contact area between the heat exchange pipes and refrigerants is larger, and the heat conduction effect is better. The circumferential turbulent flow strips are arranged on the inner pipe walls of the heat exchange pipes, refrigerants in the heat exchange pipes are disturbed to form turbulent flow, and the heat transfer efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration systems, in particular to an ultra-low temperature refrigeration system. Background Art

[0002] An ultra-low temperature refrigeration system usually includes a primary refrigeration system and a secondary refrigeration system. The primary refrigeration system cools the refrigerant of the secondary refrigeration system. On this basis, the refrigerant of the secondary refrigeration system can be reduced to an ultra-low temperature of dozens of degrees below zero after being depressurized by the secondary refrigeration system. The primary and secondary refrigeration systems are respectively provided with primary and secondary heat exchange tubes, and the primary and secondary heat exchange tubes are in contact with each other for heat exchange. In a conventional ultra-low temperature refrigeration system, both the primary and secondary heat exchange tubes are circular tubes, and the contact mode of the heat exchange tubes is line contact, with a small contact area and low heat exchange efficiency. The patent document CN218379961U discloses an ultra-low temperature refrigeration system, which discloses 4 different methods, all of which can increase the contact area of the heat exchange tubes. Among them, 3 methods are to directly contact the heat exchange tubes for heat conduction: (1) Among two heat exchange tubes, one is sleeved outside the other, and the two heat exchange tubes are in curved surface contact; (2) The two heat exchange tubes are designed as "D" - shaped tubes, and the flat surfaces of the two heat exchange tubes are attached together, and the two heat exchange tubes are in flat surface contact; (3) The two heat exchange tubes are designed as rectangular tubes, and the flat surfaces of the two heat exchange tubes are attached together, and the two heat exchange tubes are in flat surface contact. Among the above 3 methods, in the first method, the two heat exchange tubes are in curved surface contact, with the largest contact area and the highest heat exchange efficiency. However, the disadvantage is that: the inner heat exchange tube needs to be connected to other components of the refrigeration system. Therefore, the outer heat exchange tube must be provided with a tube - passing hole, and the inner heat exchange tube extends from the tube - passing hole to the outside to connect to other components of the refrigeration system, and the refrigerant in the outer heat exchange tube is likely to leak to the outside from the tube - passing hole. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide an ultra-low temperature refrigeration system, in which the primary and secondary heat exchange tubes are in curved surface contact, with a large heat exchange area and high heat exchange efficiency. On this basis, the refrigerant in the heat exchange tubes is not likely to leak.

[0004] To solve the above technical problem, the ultra-low temperature refrigeration system of the utility model includes a primary refrigeration system and a secondary refrigeration system. The primary and secondary refrigeration systems are respectively provided with primary and secondary heat exchange tubes. The heat exchange tubes have heat exchange surfaces. The two heat exchange tubes are arranged side by side laterally, and the heat exchange surfaces of the two heat exchange tubes are in direct contact for heat exchange. The primary refrigeration system cools the refrigerant of the secondary refrigeration system in this way. The heat exchange surfaces of the two heat exchange tubes are complementary wavy curved surfaces.

[0005] The refrigeration system provided by the utility model has complementary wavy curved surfaces on the heat exchange surfaces of the first-stage and second-stage heat exchange tubes. The two heat exchange tubes exchange heat through direct contact of the curved surfaces, with a large heat exchange area and high heat exchange efficiency. The first-stage and second-stage heat exchange tubes are arranged side by side laterally, unlike the prior art where one is sleeved outside the other, so there is no need to drill through holes in the tube wall of one of them as in the prior art, and the refrigerant in the heat exchange tubes is not easily leaked to the outside.

[0006] Furthermore, a heat-conducting material is sleeved outside the two heat exchange tubes. The heat-conducting material is specifically heat-conducting silica gel, and a heat-insulating sleeve is sleeved outside the heat-conducting material. The upper, lower, and left outer surfaces of the first-stage heat exchange tube are indirectly in contact with the upper, lower, and right outer surfaces of the second-stage heat exchange tube through the heat-conducting material, and indirect heat exchange is carried out in this way.

[0007] Furthermore, the inner tube wall of the heat exchange tube is located on the back of the heat exchange surface and is provided with axial grooves and / or axial protrusions, and the axial grooves and / or axial protrusions are in a three-dimensional spiral shape; in the case of the same inner tube wall length, the three-dimensional spiral grooves and protrusions are longer than the linear grooves and protrusions, have a larger contact area with the refrigerant, and have better heat conduction effect.

[0008] Furthermore, the inner tube wall of the heat exchange tube is provided with circumferential turbulators, and the circumferential turbulators can disturb the refrigerant in the first-stage heat exchange tube to form a turbulent flow in the first-stage heat exchange tube. When the refrigerant is in a turbulent state, the vortices and mixing inside the refrigerant can improve the heat transfer efficiency. Description of the Drawings

[0009] Figure 1 is a schematic diagram of an ultra-low temperature refrigeration system

[0010] Figure 2 is a three-dimensional view of the heat exchange tube.

[0011] Figure 3 is a top view of the heat exchange tube.

[0012] Figure 4 is Figure 3 the A-A sectional view of

[0013] Figure 5 is Figure 3 the B-B sectional view of

[0014] Figure 6 is a three-dimensional view of the first-stage heat exchange tube. Detailed Description of the Invention

[0015] The following further elaborates on the present invention in detail in conjunction with specific embodiments.

[0016] Figure 1The ultra-low temperature refrigeration system shown includes a primary refrigeration system 100 and a secondary refrigeration system 200: The primary refrigeration system 100 includes a compressor 1001, a condenser 1003, a first expansion valve 1002, and a first evaporator 1004 connected together. The secondary refrigeration system 200 includes a second expansion valve 2002 and a second evaporator 2001. The first evaporator 1004 of the primary refrigeration system 100 serves as the condenser of the secondary refrigeration system 200 and is connected to the second expansion valve 2002 and the second evaporator 2001 of the secondary refrigeration system 200. The primary refrigeration system 100 exchanges heat with the secondary refrigeration system 200 through the first evaporator 1004 to cool the refrigerant in the secondary refrigeration system 200, so that the refrigerant in the secondary refrigeration system 200 can be reduced to an ultra-low temperature of dozens of degrees below zero after being decompressed by the secondary refrigeration system 200. This is the prior art. The first evaporator 1004 includes a primary heat exchange tube 1 and a secondary heat exchange tube 2 arranged side by side left and right. The primary heat exchange tube 1 is on the left and serves as the evaporation tube of the primary refrigeration system 100, connecting the compressor 1001, the condenser 1003, and the first expansion valve 1002 of the primary refrigeration system 100. The secondary heat exchange tube 2 is on the right and serves as the condensation tube of the secondary refrigeration system 200, connecting the second expansion valve 2002 and the second evaporator 2001 of the secondary refrigeration system 200. See Figure 3 , Figure 4 and Figure 5 , the outer wall on the right side of the primary heat exchange tube 1 is the first heat exchange surface 11, and the outer wall on the left side of the secondary heat exchange tube 2 is the second heat exchange surface 21. The first heat exchange surface 11 and the second heat exchange surface 21 are wavy curved surfaces that are complementary in concavity and convexity, and these two heat exchange surfaces 11, 21 are in direct contact for heat exchange. The primary refrigeration system 100 (see Figure 1 ) cools the refrigerant of the secondary refrigeration system 200 (see Figure 1 ) in this way. Since the first heat exchange surface 11 and the second heat exchange surface 21 are wavy curved surfaces that are complementary in concavity and convexity, the primary heat exchange tube 1 and the secondary heat exchange tube 2 exchange heat in a direct contact manner through the first heat exchange surface 11 and the second heat exchange surface 21, with a large contact area and high heat exchange efficiency. The primary heat exchange tube 1 and the secondary heat exchange tube 2 are arranged side by side laterally on the left and right, unlike the prior art where one is sleeved outside the other, so there is no need to drill through holes in the wall of one of them as in the prior art, and the refrigerant in the heat exchange tubes 1, 2 is not likely to leak to the outside.

[0017] Such as Figure 5 and Figure 6As shown in the figure, the right inner tube wall 10 of the primary heat exchange tube 1 is located on the back of the first heat exchange surface 11. Axial grooves 13 and axial protrusions 14 are provided on the right inner tube wall 10. The left inner tube wall 20 of the secondary heat exchange tube 2 is located on the back of the second heat exchange surface 21. Axial grooves 23 and axial protrusions 24 are also provided on the left inner tube wall 20. This can increase the heat conduction area of the inner tube walls 10 and 20 of the primary and secondary heat exchange tubes 1 and 2, and improve the heat conduction effect. The grooves 13, 23 and protrusions 14, 24 on the inner tube walls 10, 20 of the primary and secondary heat exchange tubes 1 and 2 are all three-dimensional spiral shapes. When the lengths of the inner tube walls 10 and 20 are the same, the three-dimensional spiral grooves 13, 23, protrusions 14, 24 are longer than the straight grooves and protrusions, have a larger contact area with the refrigerant, and a better heat conduction effect. The right inner tube wall 10 of the primary heat exchange tube 1 is provided with circumferential turbulators 15. The circumferential turbulators 15 can disturb the refrigerant in the primary heat exchange tube 1 and form a turbulent flow in the primary heat exchange tube 1. When the refrigerant is in a turbulent state, the vortices and mixing inside the refrigerant can improve the heat transfer efficiency. The left inner tube wall 20 of the secondary heat exchange tube 2 is located on the back of the second heat exchange surface 21. The left inner tube wall 20 is also provided with circumferential turbulators 15, which will not be elaborated here.

[0018] As Figure 2 shown, a heat conduction material 3 made of heat-conducting silica gel is sleeved outside the primary heat exchange tube 1 and the secondary heat exchange tube 2, and a heat insulation sleeve 4 is sleeved outside the heat conduction material 3. The upper, lower and left outer surfaces of the primary heat exchange tube 1 are indirectly in contact with the upper, lower and right outer surfaces of the secondary heat exchange tube 2 through the heat conduction material 3, and indirect heat exchange is carried out in this way.

[0019] In other embodiments, the heat conduction material 3 and the heat insulation sleeve 4 can be cancelled.

[0020] In other embodiments, the axial grooves 13, 23 or axial protrusions 14, 24 or circumferential turbulators 15 on the inner tube wall of the heat exchange tube can be cancelled.

[0021] In other embodiments, the axial grooves 13, 23 or axial protrusions 14, 24 on the inner tube wall of the heat exchange tube can be not spiral, but changed to straight.

[0022] In other embodiments, the axial grooves 13, 23 or axial protrusions 14, 24 can be provided on the inner tube wall of the heat exchange tubes 1, 2 away from the heat exchange surfaces 11, 12, for example, on the inner tube wall 10 of the primary heat exchange tube 1 or the inner tube wall 20 of the secondary heat exchange tube 2.

[0023] In other embodiments, it can be changed to that only the inner tube wall of one heat exchange tube is provided with axial grooves 13, 23, axial protrusions 14, 24 and circumferential turbulators 15.

[0024] As described above, it is only the implementation mode of the present invention, and does not limit the scope of patent protection. Those skilled in the art make non-substantive changes or substitutions based on the present invention, and still fall within the scope of patent protection.

Claims

1. An ultra-low temperature refrigeration system, comprising a primary refrigeration system and a secondary refrigeration system, wherein the primary refrigeration system and the secondary refrigeration system are respectively provided with a primary heat exchange tube and a secondary heat exchange tube, the two heat exchange tubes are arranged side by side, the heat exchange tubes have a heat exchange surface, the heat exchange surfaces of the two heat exchange tubes are in direct contact for heat exchange, and the primary refrigeration system cools down the refrigerant of the secondary refrigeration system in this way, and the characteristics are: The heat exchange surfaces of the two heat exchange tubes are wavy curved surfaces with complementary concave and convex portions.

2. The ultra-low temperature refrigeration system according to claim 1, characterized in that: The outer sides of the two heat exchange tubes are covered with heat conducting materials.

3. The ultra-low temperature refrigeration system according to claim 2, characterized in that: The thermal conductive material is specifically thermal conductive silicone.

4. The ultra-low temperature refrigeration system according to claim 2, characterized in that: The outer side of the heat-conducting material is covered with a heat-insulating sleeve.

5. The ultra-low temperature refrigeration system according to claim 1, characterized in that: The inner tube wall of at least one heat exchange tube is provided with an axial groove and / or an axial protrusion.

6. The ultra-low temperature refrigeration system according to claim 5, characterized in that: The axial groove and / or the axial protrusion are in a three-dimensional spiral shape.

7. The ultra-low temperature refrigeration system according to claim 5, characterized in that: The inner tube wall is located on the back side of the heat exchange surface.

8. The ultra-low temperature refrigeration system according to claim 1, characterized in that: The inner tube wall of at least one heat exchange tube is provided with a circumferential spoiler strip.

9. The ultra-low temperature refrigeration system according to claim 8, characterized in that: The inner tube wall is arranged on the back side of the heat exchange surface.

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