Ultralow-temperature precise constant-temperature device based on liquid nitrogen refrigeration

Abstract

The invention relates to the technical field of liquid nitrogen refrigeration, in particular to a liquid nitrogen refrigeration-based ultralow-temperature precise constant-temperature device which comprises a liquid nitrogen tank and a constant-temperature tank, an inner box is arranged in the constant-temperature tank, an outer ring body is arranged on the outer surface of the constant-temperature tank, an air suction assembly is arranged on the outer surface of the outer ring body, and an exhaust assembly is arranged on the outer surface of the constant-temperature tank. A nitrogen tank is arranged at the end, away from the constant-temperature tank, of the exhaust assembly, a butt-joint pipe is arranged between the liquid nitrogen tank and the constant-temperature tank, and a butt-joint assembly is arranged on the outer surface of the butt-joint pipe. Compared with the prior art, the constant-temperature tank and the outer ring body are communicated through the air exhaust assembly, a motor is used for driving a rotary disc to rotate to drive a shifting block to pull a strip-shaped plate to move up and down, the strip-shaped plate drives a first one-way valve to move up and down to extrude or stretch the upper part and the lower part of a corrugated pipe, and the outer ring body is filled with nitrogen in the constant-temperature tank; and the effect of cooling the outer surface of the constant-temperature tank is achieved, the gasification speed of liquid nitrogen is reduced, and the energy-saving effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of liquid nitrogen refrigeration, and in particular to an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration. Background Art

[0002] Liquid nitrogen refrigeration device is a device that uses the ultra-low temperature characteristics of liquid nitrogen for refrigeration. The boiling point of liquid nitrogen is extremely low, at -196°C. It can quickly absorb heat under normal pressure to achieve rapid freezing. The liquid nitrogen refrigeration equipment contains a constant temperature device, which is a device that can provide a stable and reliable ultra-low temperature environment. It combines the refrigeration capacity of liquid nitrogen and a precise constant temperature control system to meet the high requirements of scientific research, production and other fields for ultra-low temperature environments.

[0003] In the prior art, a Chinese patent document with publication number CN113941385B, a ultra-low temperature precision constant temperature device and temperature control method based on liquid nitrogen refrigeration, proposes a constant temperature device, including a tank body and a shell, a guide tube is arranged in the tank body, and the upper and lower ends of the guide tube have vents, an air circulation mechanism includes a circulation fan, which is installed on the inner side of the lower edge of the guide tube, an air heating mechanism includes a temperature sensor and an annular heating belt, a measuring end of the temperature sensor is arranged in the guide tube, and the annular heating belt is arranged between the outer side of the guide tube and the inner side of the tank body, and a liquid nitrogen injection mechanism includes a fast liquid nitrogen diffusion ring, a slow liquid nitrogen diffusion ring, an ultra-low temperature relay and a liquid nitrogen tank, liquid nitrogen is input into the insulation tank through a double liquid nitrogen diffusion ring to cool down, and a fast liquid nitrogen The diffusion ring realizes rapid cooling of the initial section, and the slow liquid nitrogen diffusion ring provides a cooling source for the temperature control of the constant section. It can quickly and evenly release liquid nitrogen to the constant temperature device without causing the temperature field inside the constant temperature device to get out of control, and can quickly generate a constant and uniform temperature field. However, the thermal insulation layer on the outer layer of the device simply relies on heat insulation for insulation, and the insulation effect is limited, resulting in liquid nitrogen being in a state of continuous volatilization, resulting in a large consumption of liquid nitrogen. When the liquid nitrogen temperature reaches the boiling point, it will gasify into nitrogen. At this time, the nitrogen temperature is also in a low state. The existing device directly recovers the nitrogen and cannot utilize it. Therefore, the present application provides an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration to meet the utilization of nitrogen and improve the insulation effect. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration to solve the problem that the insulation effect of the insulation layer is poor and nitrogen cannot be used.

[0005] Based on the above purpose, the present invention provides an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration, including a liquid nitrogen tank and a constant temperature tank, wherein an inner box is arranged inside the constant temperature tank, an outer ring body is arranged on the outer surface of the constant temperature tank, a vacuum assembly is arranged on the outer surface of the outer ring body, an exhaust assembly is arranged on the outer surface of the constant temperature tank, a nitrogen tank is arranged on one end of the exhaust assembly away from the constant temperature tank, a butt joint is arranged between the liquid nitrogen tank and the constant temperature tank, and a butt joint assembly is arranged on the outer surface of the butt joint; The vacuum assembly is connected to the constant temperature tank and the outer ring body, the exhaust assembly is connected to the outer ring body and the nitrogen tank, and the exhaust assembly and the vacuum assembly are used together to extract nitrogen.

[0006] Preferably, the vacuum assembly includes a protective box fixedly connected to the outer surface of the outer ring body, a motor is provided on the outer surface of the protective box, a turntable is fixedly connected to the driving end of the motor, a shift block is fixedly connected to the outer surface of the turntable, an upper pipe is provided at the top of the protective box, a lower pipe is provided at the bottom end of the protective box, a bellows is provided between the upper pipe and the lower pipe, and a first one-way valve is provided in the middle of the bellows.

[0007] Preferably, a strip plate is fixedly connected to the outer surface of the first one-way valve, a strip groove is formed on a side of the strip plate away from the first one-way valve, and the shift block slides inside the strip groove.

[0008] Preferably, a second one-way valve is provided at both the upper and lower ends of the bellows, the upper pipe is connected to the upper end of the bellows through the second one-way valve, the end of the upper pipe away from the bellows is fixed to the upper outer surface of the thermostatic tank, the lower pipe is connected to the lower end of the bellows through the second one-way valve, and the end of the lower pipe away from the bellows is fixed to the lower outer surface of the outer ring body.

[0009] Preferably, the exhaust assembly includes an air collecting pipe fixedly connected to the upper outer surface of the outer ring body, one end of the air collecting pipe away from the outer ring body is fixedly connected to the top of the nitrogen tank, a sphere is arranged inside the air collecting pipe, and a through hole is opened in the middle of the outer surface of the sphere.

[0010] Preferably, a transmission rod is fixedly connected to the bottom end of the sphere, the bottom end of the transmission rod is inserted into the interior of the lower pipe, the bottom end of the transmission rod is fixedly connected to a central shaft, and fan plates are distributed circumferentially on the outer surface of the central shaft.

[0011] Preferably, the docking assembly includes a docking tube sleeved on the outer surface of the connecting tube, a rotating shaft is movably provided in the middle of the docking tube, an inner rod is fixedly connected to the interior of the rotating shaft, a threaded rod is fixedly connected to the end of the inner rod, a threaded sleeve is threadedly sleeved on the outer surface of the threaded rod, a push rod is hinged on the outer surface of the threaded sleeve, and an arc block is hinged on the end of the push rod away from the threaded sleeve.

[0012] Preferably, two threaded rods are provided and symmetrically arranged at both ends of the inner rod, the threaded rod is arranged in a T shape, the inner wall of the arc block is fixedly connected with a positioning rod, and the end of the positioning rod away from the arc block is movably inserted into the end of the threaded rod.

[0013] Preferably, an extension rod is fixedly connected to the outer surface of the threaded sleeve, a sliding groove is provided on the inner wall of the butt joint tube, and the extension rod slides inside the sliding groove.

[0014] Preferably, both ends of the butt-jointing pipe are provided with mounting grooves, and the ends of the connecting pipe are clamped in the mounting grooves.

[0015] Beneficial effects of the present invention: 1. This ultra-low temperature precision constant temperature device connects the constant temperature tank and the outer ring body by arranging an exhaust component, and uses a motor to drive the turntable to rotate and drive the shift block to pull the strip plate up and down. The strip plate drives the first one-way valve to move up and down to squeeze or stretch the upper and lower parts of the bellows. Under the action of the second one-way valve, the nitrogen in the constant temperature tank is pumped into the lower pipeline and then flows into the outer ring body, so that the nitrogen fills the outer ring body, thereby achieving the effect of cooling the outer surface of the constant temperature tank, reducing the gasification rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving.

[0016] 2. This ultra-low temperature precision constant temperature device is connected to the exhaust component by arranging an exhaust component. When nitrogen flows in the lower pipe, it will impact the fan plate, push the fan plate to drive the central axis to rotate, and then drive the sphere to rotate through the transmission rod. The nitrogen in the outer ring body will flow into the gas collecting pipe through the through hole under the action of pressure, and then be collected in the nitrogen tank. Because the rotation of the sphere is indirect under the action of the exhaust component, it can not only collect nitrogen, but also block nitrogen, avoid continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body. Then, the temperature conversion effect of nitrogen can improve the thermal insulation effect of the outer ring body.

[0017] 3. This ultra-low temperature precision constant temperature device connects the connecting pipe by setting a docking assembly. The ends of the docking pipe are clamped in the installation groove. The rotating shaft drives the inner rod to rotate. Under the action of the threaded rod and the threaded sleeve, and the limitation of the positioning rod, the extension rod and the slide groove, the driving push rod pushes the arc block to expand outward. The arc block is squeezed on the inner wall of the docking pipe, so that the joint between the docking pipe and the connecting pipe is pressed tightly, reducing the risk of leakage and improving the safety performance of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 This is a schematic diagram of the structure of the air extraction component of the present invention; Figure 3 This is a schematic diagram of the internal structure of the protection box of the present invention; Figure 4 It is a schematic diagram of the exhaust assembly structure of the present invention; Figure 5 This is a schematic diagram of the docking assembly structure of the present invention; Figure 6 It is a schematic diagram of the internal structure of the butt-jointed pipe of the present invention.

[0020] The markings in the figure are: 1. Liquid nitrogen tank; 2. Constant temperature tank; 3. Inner box; 4. Outer ring; 5. Pumping assembly; 501. Protective box; 502. Motor; 503. Turntable; 504. Dial block; 505. Strip plate; 506. First one-way valve; 507. Upper pipe; 508. Lower pipe; 509. Bellows; 510. Second one-way valve; 511. Strip groove; 6. Nitrogen tank; 7. Exhaust assembly; 701. Collector Air pipe; 702, sphere; 703, through hole; 704, transmission rod; 705, central axis; 706, fan plate; 8, connecting pipe; 9, docking assembly; 901, docking tube; 902, rotating shaft; 903, inner rod; 904, threaded rod; 905, threaded sleeve; 906, push rod; 907, arc block; 908, positioning rod; 909, mounting groove; 910, extension rod; 911, slide groove. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0022] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] like Figures 1 to 6 As shown, an ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration includes a liquid nitrogen tank 1 and a constant temperature tank 2, an inner box 3 is arranged inside the constant temperature tank 2, an outer ring body 4 is arranged on the outer surface of the constant temperature tank 2, a gas extraction component 5 is arranged on the outer surface of the outer ring body 4, an exhaust component 7 is arranged on the outer surface of the constant temperature tank 2, a nitrogen tank 6 is arranged on the end of the exhaust component 7 away from the constant temperature tank 2, a docking pipe 901 is arranged between the liquid nitrogen tank 1 and the constant temperature tank 2, a docking component 9 is arranged on the outer surface of the docking pipe 901, the gas extraction component 5 connects the constant temperature tank 2 and the outer ring body 4, the exhaust component 7 connects the outer ring body 4 and the nitrogen tank 6, and the exhaust component 7 cooperates with the gas extraction component 5 to extract nitrogen; Nitrogen is extracted by the vacuum assembly 5 and discharged into the outer ring body 4, so that the nitrogen fills the outer ring body 4, thereby achieving the effect of cooling the outer surface of the constant temperature tank 2, and reusing the low temperature of the nitrogen, thereby reducing the gasification rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving. In addition, the nitrogen in the outer ring body 4 is recovered by the exhaust assembly 7 and stored in the nitrogen tank 6. A docking device is provided at the joint of the connecting pipe 8 between the liquid nitrogen tank 1 and the constant temperature tank 2 to improve the sealing effect of the docking, avoid leakage, and improve the safety performance of the device.

[0024] like Figure 2 and Figure 3As shown, the air extraction component 5 includes a protective box 501 fixedly connected to the outer surface of the outer ring body 4, the outer surface of the protective box 501 is provided with a motor 502, the driving end of the motor 502 is fixedly connected to a turntable 503, the outer surface of the turntable 503 is fixedly connected to a dial block 504, the top of the protective box 501 is provided with an upper pipe 507, the bottom of the protective box 501 is provided with a lower pipe 508, a bellows 509 is provided between the upper pipe 507 and the lower pipe 508, the middle of the bellows 509 is provided with a first one-way valve 506, and the outer surface of the first one-way valve 506 is fixedly connected to a strip plate 5 05, a strip groove 511 is provided on one side of the strip plate 505 away from the first one-way valve 506, the shift block 504 slides inside the strip groove 511, and the second one-way valve 510 is provided at both upper and lower ends of the bellows 509, the upper pipe 507 is connected to the upper end of the bellows 509 through the second one-way valve 510, and one end of the upper pipe 507 away from the bellows 509 is fixed to the upper outer surface of the thermostatic tank 2, and the lower pipe 508 is connected to the lower end of the bellows 509 through the second one-way valve 510, and one end of the lower pipe 508 away from the bellows 509 is fixed to the lower outer surface of the outer ring body 4; The motor 502 drives the turntable 503 to rotate. During the rotation of the turntable 503, the shifting block 504 is driven to make a circular motion around the center of the turntable 503. Since the shifting block 504 is placed in the strip groove 511 on the outer surface of the strip plate 505, the shifting block 504 drives the strip plate 505 and the first one-way valve 506 to make an up and down reciprocating motion during the movement. During the downward movement of the first one-way valve 506, the upper part of the bellows 509 is stretched, and the nitrogen is flowed from the upper pipe 507 through the second one-way valve 510 into the upper half of the bellows 509, and at the same time, the lower half of the bellows 509 is squeezed, so that the lower half of the bellows 509 can be reciprocated. 9 flows into the lower pipe 508 from the second one-way valve 510. As the turntable 503 rotates, the first one-way valve 506 stretches the lower half bellows 509 and squeezes the upper half bellows 509 during the upward movement, so that the nitrogen in the upper half bellows 509 can be pressed into the lower half bellows 509 through the first one-way valve 506. This reciprocating process can realize the nitrogen in the thermostatic tank 2 being drawn into the lower pipe 508 and then flowing into the outer ring body 4, so that the nitrogen fills the outer ring body 4, achieving the effect of cooling the outer surface of the thermostatic tank 2, reducing the gasification rate of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving.

[0025] like Figure 1 , Figure 2 and Figure 4As shown, the exhaust assembly 7 includes an air collecting pipe 701 fixedly connected to the upper part of the outer surface of the outer ring body 4, and one end of the air collecting pipe 701 away from the outer ring body 4 is fixedly connected to the top of the nitrogen tank 6. A sphere 702 is arranged inside the air collecting pipe 701, and a through hole 703 is opened through the middle of the outer surface of the sphere 702. A transmission rod 704 is fixedly connected to the bottom end of the sphere 702, and the bottom end of the transmission rod 704 is inserted into the interior of the lower pipe 508. The bottom end of the transmission rod 704 is fixedly connected to a central shaft 705, and the outer surface of the central shaft 705 is circumferentially distributed with fan plates 706; When the nitrogen flows in the lower pipe 508, it will impact the fan plate 706, push the fan plate 706 to drive the central axis 705 to rotate, and then drive the sphere 702 to rotate through the transmission rod 704. The outer surface of the sphere 702 is penetrated by a through hole 703. When the through hole 703 is connected to the gas collecting pipe 701, the nitrogen in the outer ring body 4 will flow into the gas collecting pipe 701 through the through hole 703 under the action of pressure, and then be collected in the nitrogen tank 6. Because under the action of the vacuum component 5, the nitrogen flows into the lower pipe 508 indirectly, and then the rotation of the sphere 702 is also indirect, which can not only realize the collection of nitrogen, but also realize the blocking of nitrogen, avoid the continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body 4, and then improve the thermal insulation effect of the outer ring body 4 through the temperature conversion effect of nitrogen.

[0026] like Figure 5 and Figure 6 As shown, the docking assembly 9 includes a docking tube 901 sleeved on the outer surface of the connecting tube 8, a rotating shaft 902 is movably provided in the middle of the docking tube 901, an inner rod 903 is fixedly connected to the interior of the rotating shaft 902, a threaded rod 904 is fixedly connected to the end of the inner rod 903, a threaded sleeve 905 is threadedly sleeved on the outer surface of the threaded rod 904, a push rod 906 is hinged on the outer surface of the threaded sleeve 905, an arc block 907 is hinged on one end of the push rod 906 away from the threaded sleeve 905, and the threaded rod 904 is provided with two and symmetrically arranged At both ends of the inner rod 903, the threaded rod 904 is set to a T shape, the inner wall of the arc block 907 is fixedly connected with a positioning rod 908, and the end of the positioning rod 908 away from the arc block 907 is movably inserted into the end of the threaded rod 904, and the outer surface of the threaded sleeve 905 is fixedly connected with an extension rod 910, and the inner wall of the butt tube 901 is provided with a slide groove 911, and the extension rod 910 slides inside the slide groove 911, and both ends of the butt tube 901 are provided with installation grooves 909, and the end of the connecting pipe 8 is clamped inside the installation groove 909; The rotating shaft 902 drives the inner rod 903 to rotate, and the rotation of the inner rod 903 drives the threaded rod 904 to rotate. The outer surface of the threaded rod 904 is sleeved with a threaded sleeve 905, and the extension rod 910 on the outer surface of the threaded sleeve 905 is limited in the slide groove 911, and then the rotation of the threaded rod 904 drives the threaded sleeve 905 to move along the threaded rod 904. The outer surface of the threaded sleeve 905 is hinged with an arc block 907 through the push rod 906, and the inner wall of the arc block 907 is inserted in the end round block of the threaded rod 904 through the positioning rod 908, and then the movement of the threaded sleeve 905 pushes the arc block 907 to expand outward, so that the arc block 907 is squeezed on the inner wall of the butt joint 901, so that the joint between the butt joint 901 and the connecting pipe 8 is pressed tightly, reducing the risk of leakage and improving the safety performance of the device.

[0027] The technical solution provided by the present invention is to put the articles to be refrigerated into the inner box 3, and the liquid nitrogen tank 1 transports liquid nitrogen into the constant temperature tank 2 through the connecting pipe 8 to achieve the effect of constant temperature refrigeration. The liquid nitrogen placed in the constant temperature tank 2 will be gasified when the temperature rises, and the nitrogen is extracted by the exhaust component 5 and discharged into the outer ring body 4, so that the nitrogen fills the outer ring body 4, so as to achieve the effect of cooling the outer surface of the constant temperature tank 2, and reuse the low temperature of the nitrogen, thereby reducing the gasification speed of the liquid nitrogen, reducing the consumption of the liquid nitrogen, and achieving the effect of energy saving. In addition, the nitrogen in the outer ring body 4 is recovered and stored in the nitrogen tank 6 through the exhaust component 7. A docking device is provided at the joint of the connecting pipe 8 between the liquid nitrogen tank 1 and the constant temperature tank 2 to improve the sealing effect of the docking, avoid leakage, and improve the safety performance of the device. Specifically, the motor 502 drives the turntable 503 to rotate. During the rotation of the turntable 503, the shifting block 504 will be driven to make a circular motion around the center of the turntable 503. Since the shifting block 504 is placed in the strip groove 511 on the outer surface of the strip plate 505 The shift block 504 will drive the strip plate 505 and the first one-way valve 506 to do up and down reciprocating motion during the movement. The first one-way valve 506 will stretch the upper part of the bellows 509 during the downward movement, and then the nitrogen will flow from the upper pipe 507 into the upper half of the bellows 509 through the second one-way valve 510. At the same time, the lower half of the bellows 509 is squeezed, and the nitrogen in the lower half of the bellows 509 can flow from the second one-way valve 510 into the lower pipe 508. As the turntable 503 rotates, the first one-way valve 506 During the upward movement of the one-way valve 506, the lower half bellows 509 will be stretched and the upper half bellows 509 will be squeezed, so that the nitrogen in the upper half bellows 509 can be pressed into the lower half bellows 509 through the first one-way valve 506, and the nitrogen in the thermostatic tank 2 is pumped into the lower pipe 508 and then flows into the outer ring body 4, so that the nitrogen fills the outer ring body 4, achieving the effect of cooling the outer surface of the thermostatic tank 2, reducing the gasification speed of liquid nitrogen, reducing the consumption of liquid nitrogen, and achieving the effect of energy saving; When the nitrogen flows in the lower pipe 508, it will impact the fan plate 706, push the fan plate 706 to drive the central axis 705 to rotate, and then drive the ball 702 to rotate through the transmission rod 704. The outer surface of the ball 702 is penetrated with a through hole 703. When the through hole 703 is connected to the gas collecting pipe 701, the nitrogen in the outer ring body 4 will flow into the gas collecting pipe 701 through the through hole 703 under the action of pressure, and then be collected in the nitrogen tank 6. Because under the action of the exhaust component 5, the nitrogen flows into the lower pipe 508 indirectly, and then the rotation of the ball 702 is also indirect, which can realize the collection of nitrogen and the blocking of nitrogen, avoid the continuous removal of nitrogen, and increase the retention time of nitrogen in the outer ring body 4. Then, through the temperature conversion effect of nitrogen, the thermal insulation effect of the outer ring body 4 is improved; The docking tube 901 is connected by the docking assembly 9, and the ends of the docking tube 901 are all clamped in the installation groove 909. At this time, the rotating shaft 902 drives the inner rod 903 to rotate, and the rotation of the inner rod 903 drives the threaded rod 904 to rotate. The outer surface of the threaded rod 904 is sleeved with a threaded sleeve 905, and the extension rod 910 on the outer surface of the threaded sleeve 905 is limited in the slide groove 911, and then the rotation of the threaded rod 904 drives the threaded sleeve 905 to move along the threaded rod 904. The outer surface of the threaded sleeve 905 is hinged with an arc block 907 through the push rod 906, and the inner wall of the arc block 907 is inserted in the end round block of the threaded rod 904 through the positioning rod 908, and then the movement of the threaded sleeve 905 pushes the arc block 907 to expand outward, so that the arc block 907 is squeezed on the inner wall of the docking tube 901, so that the connection between the docking tube 901 and the connecting pipe 8 is pressed tightly, reducing the risk of leakage and improving the safety performance of the device.

[0028] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0029] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration, characterized in that: include: A liquid nitrogen tank (1) and a constant temperature tank (2), wherein an inner box (3) is arranged inside the constant temperature tank (2), an outer ring body (4) is arranged on the outer surface of the constant temperature tank (2), an exhaust assembly (5) is arranged on the outer surface of the outer ring body (4), an exhaust assembly (7) is arranged on the outer surface of the constant temperature tank (2), a nitrogen tank (6) is arranged at one end of the exhaust assembly (7) away from the constant temperature tank (2), a butt joint (901) is arranged between the liquid nitrogen tank (1) and the constant temperature tank (2), and a butt joint assembly (9) is arranged on the outer surface of the butt joint (901); The exhaust component (5) is connected to the constant temperature tank (2) and the outer ring body (4), the exhaust component (7) is connected to the outer ring body (4) and the nitrogen tank (6), and the exhaust component (7) cooperates with the exhaust component (5) to extract nitrogen.

2. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 1, characterized in that: The air extraction assembly (5) comprises a protective box (501) fixedly connected to the outer surface of the outer ring body (4); a motor (502) is arranged on the outer surface of the protective box (501); a driving end of the motor (502) is fixedly connected to a rotating disk (503); a shifting block (504) is fixedly connected to the outer surface of the rotating disk (503); an upper pipe (507) is arranged at the top end of the protective box (501); a lower pipe (508) is arranged at the bottom end of the protective box (501); a bellows (509) is arranged between the upper pipe (507) and the lower pipe (508); and a first one-way valve (506) is arranged in the middle of the bellows (509).

3. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 2, characterized in that: A strip plate (505) is fixedly connected to the outer surface of the first one-way valve (506); a strip groove (511) is provided on a side of the strip plate (505) away from the first one-way valve (506); and the shifting block (504) slides inside the strip groove (511).

4. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 3, characterized in that: The upper and lower ends of the bellows (509) are both provided with a second one-way valve (510); the upper pipe (507) is connected to the upper end of the bellows (509) via the second one-way valve (510); one end of the upper pipe (507) away from the bellows (509) is fixed to the upper part of the outer surface of the thermostatic tank (2); the lower pipe (508) is connected to the lower end of the bellows (509) via the second one-way valve (510); one end of the lower pipe (508) away from the bellows (509) is fixed to the lower part of the outer surface of the outer ring body (4).

5. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 4, characterized in that: The exhaust assembly (7) comprises an air collecting pipe (701) fixedly connected to the upper part of the outer surface of the outer ring body (4); one end of the air collecting pipe (701) away from the outer ring body (4) is fixedly connected to the top of the nitrogen tank (6); a sphere (702) is arranged inside the air collecting pipe (701); a through hole (703) is opened through the middle of the outer surface of the sphere (702).

6. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 5, characterized in that: The bottom end of the sphere (702) is fixedly connected to a transmission rod (704), the bottom end of the transmission rod (704) is inserted into the interior of the lower pipe (508), the bottom end of the transmission rod (704) is fixedly connected to a central shaft (705), and the outer surface of the central shaft (705) is circumferentially distributed with fan plates (706).

7. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 6, characterized in that: The docking assembly (9) comprises a docking tube (901) sleeved on the outer surface of the connecting tube (8); a rotating shaft (902) is movably provided in the middle of the docking tube (901); an inner rod (903) is fixedly connected to the interior of the rotating shaft (902); a threaded rod (904) is fixedly connected to the end of the inner rod (903); a threaded sleeve (905) is threadedly sleeved on the outer surface of the threaded sleeve (905); a push rod (906) is hingedly connected to the outer surface of the threaded sleeve (905); and an arc block (907) is hingedly connected to one end of the push rod (906) away from the threaded sleeve (905).

8. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 7, characterized in that: Two threaded rods (904) are provided and symmetrically arranged at both ends of the inner rod (903); the threaded rod (904) is arranged in a T shape; a positioning rod (908) is fixedly connected to the inner wall of the arc block (907); and one end of the positioning rod (908) away from the arc block (907) is movably inserted into the end of the threaded rod (904).

9. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 8, characterized in that: An extension rod (910) is fixedly connected to the outer surface of the threaded sleeve (905), a sliding groove (911) is provided on the inner wall of the butt joint tube (901), and the extension rod (910) slides inside the sliding groove (911).

10. The ultra-low temperature precision constant temperature device based on liquid nitrogen refrigeration according to claim 9, characterized in that: Both ends of the butt-joint pipe (901) are provided with mounting grooves (909), and the ends of the connecting pipe (8) are clamped inside the mounting grooves (909).

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