Liquid nitrogen cooling device

Abstract

This application discloses a liquid nitrogen cooling device. The device includes a cooling tank, a cover measuring mechanism, a detection unit, and a controller. The cooling tank has a cavity for containing liquid nitrogen. A closable cover is positioned at the opening of the cooling tank, and a through hole is formed in the cover, penetrating its top and bottom surfaces. The measuring mechanism includes a float and a connecting rod. The float is located at one end of the connecting rod within the cavity, and the other end of the connecting rod passes through the through hole and extends to the outside of the cooling tank. The detection unit is mounted on the connecting rod and located outside the cooling tank. The detection unit measures the height between a preset point on the connecting rod and the cover. The controller is electrically connected to the detection unit and calculates the liquid nitrogen level in the cavity based on the received height value. The technical solution provided by this application enables automated liquid nitrogen level detection, avoiding direct contact between operators and liquid nitrogen.

Description

Technical Field

[0001] This application relates to the field of liquid nitrogen cooling technology for gearboxes, and particularly to a liquid nitrogen cooling device. Background Technology

[0002] Liquid nitrogen cooling devices are often used to create ultra-low temperature environments. They achieve the freezing treatment of workpieces (such as gearboxes) by storing liquid nitrogen in an internal cavity, and are key equipment to ensure the smooth operation of related processes.

[0003] In existing technologies, the ultra-low temperature environment inside the cooling box causes conventional electronic liquid level sensors to malfunction. Therefore, the industry often relies on manual detection. Operators need to open the cover to observe the liquid level and manually control the injection of liquid nitrogen. This not only poses a risk of frostbite caused by liquid nitrogen splashing, but also easily leads to safety hazards due to low-temperature gas leakage. Utility Model Content

[0004] The purpose of this application is to provide a liquid nitrogen cooling device that can achieve automated liquid nitrogen level detection and avoid direct contact between operators and liquid nitrogen.

[0005] This utility model provides a liquid nitrogen cooling device, comprising:

[0006] The cooling tank has an internal cavity for holding liquid nitrogen.

[0007] A cover, which can be opened and closed, is provided at the opening of the cooling box, and a through hole is provided on the cover through the top and bottom surfaces of the cover.

[0008] The measuring mechanism includes a float and a connecting rod. The float is located at one end of the connecting rod and within the receiving cavity. The other end of the connecting rod passes through the through hole and extends to the outside of the cooling box.

[0009] A detection unit is mounted on the connecting rod and located outside the cooling box. The detection unit is used to measure the height between a preset point on the connecting rod and the cover.

[0010] A controller, electrically connected to the detection unit, calculates the liquid nitrogen level in the containment cavity based on the received height value.

[0011] Beneficial effects: In this liquid nitrogen cooling device, a float is installed at one end of a connecting rod and placed inside the receiving cavity of the cooling tank. The other end of the connecting rod extends outside the cooling tank through a through hole. When the liquid nitrogen level in the receiving cavity changes, the float floats with the liquid surface, thereby causing the connecting rod to float up and down. The float senses changes in the liquid nitrogen level in the receiving cavity in real time and converts these changes into the vertical displacement of the connecting rod. A detection unit measures the height between a preset point on the connecting rod and the cover, and transmits the collected height value to the controller. The controller automatically calculates the liquid nitrogen level height based on a preset algorithm, eliminating the need for manual intervention. This improves operational safety, avoids direct contact between operators and liquid nitrogen, eliminates the risk of frostbite caused by liquid nitrogen splashing when the cover is opened, and prevents asphyxiation caused by low-temperature nitrogen leakage.

[0012] Meanwhile, since the detection unit is located outside the cooling tank, it avoids the effects of ultra-low temperatures, ensuring long-term reliable operation and effectively reducing failure frequency and maintenance costs. Furthermore, the controller relies on precise height data to calculate the liquid level, resulting in higher measurement accuracy and precise control of the liquid nitrogen injection volume, ensuring the stability of the cooling process. Compared to complex cryogenic sensors, the solution of using a measuring mechanism and detection unit to collaboratively measure the liquid level is simpler in structure, lower in manufacturing cost, and easier to install and maintain.

[0013] In one alternative embodiment, a seal is provided at the interface between the through hole and the connecting rod.

[0014] Beneficial effects: The evaporation of liquid nitrogen stored in the cavity can lead to a drop in liquid level, reduced cooling efficiency, and increased costs associated with replenishing liquid nitrogen. By installing a seal at the interface between the through-hole and the connecting rod, the seal can reduce the gap between the through-hole and the connecting rod, preventing liquid nitrogen vapor from leaking out and reducing the entry of hot outside air into the chamber. This extends the duration of the cryogenic environment and reduces energy consumption.

[0015] In one alternative embodiment, the seal is configured as thermal insulation cotton.

[0016] Beneficial effects: The insulation cotton itself has an extremely low thermal conductivity, which can effectively block heat exchange between the inside and outside of the cooling chamber, preventing the low temperature inside the cooling chamber from transferring cold energy to the outside through the gap between the through holes and the connecting rods, and reducing the loss of liquid nitrogen due to heat absorption and evaporation. At the same time, it prevents a large amount of heat from the outside ambient air from entering the cooling chamber, maintaining a stable temperature inside the cooling chamber and reducing the energy consumption of the cooling system.

[0017] In one alternative implementation, the floating element is a hollow spherical structure.

[0018] Beneficial effects: By setting the float to a spherical shape, the float can maintain a stable posture regardless of changes in liquid level. Furthermore, the buoyancy of a sphere is more evenly distributed in the liquid, allowing it to rise and fall smoothly with the liquid surface even with slight fluctuations in liquid level. This avoids displacement errors in the connecting rod caused by posture swaying, thus improving detection accuracy.

[0019] In one alternative embodiment, the floating element is made of aluminum.

[0020] Beneficial effects: Aluminum has a relatively low density compared to other metals. For the same volume, aluminum floats are lighter and can displace liquid nitrogen in a smaller volume to obtain sufficient buoyancy. This avoids sinking or floating unstably due to excessive weight, allowing them to more sensitively follow the rise and fall of the liquid surface and improving the real-time performance of liquid level detection.

[0021] In one optional embodiment, the cooling tank is provided with a liquid inlet communicating with the receiving cavity, and an electrically controlled valve is provided at the liquid inlet;

[0022] The electrically controlled valve is electrically connected to the controller, which is used to control the opening and closing of the electrically controlled valve.

[0023] Beneficial effects: The controller can automatically control the opening and closing of the electronically controlled valve based on the liquid level height fed back by the detection unit, eliminating the need for manual operation of liquid nitrogen injection, avoiding delays or misjudgments that may be caused by manual operation, and improving the timeliness and accuracy of liquid level control.

[0024] In one optional implementation, when the liquid nitrogen level in the containment cavity reaches a preset height, the controller controls the electronically controlled valve to close.

[0025] Beneficial effects: When the liquid nitrogen level reaches the preset height, the controller promptly closes the electrically controlled valve, limiting the amount of liquid nitrogen injected and preventing overflow or excessive evaporation due to overfilling. This reduces unnecessary material loss and lowers operating costs. There is no need for continuous manual monitoring of the liquid level and manual valve closure; the controller automatically closes the valve based on the preset height, further freeing up manpower, reducing the labor intensity of manual operation, and making the automated operation of the entire liquid nitrogen cooling system more efficient and reliable.

[0026] In one optional embodiment, the liquid nitrogen cooling device further includes an alarm unit electrically connected to the controller;

[0027] When the liquid nitrogen level in the containment cavity reaches a preset height and the electronically controlled valve is in the open state, the controller controls the alarm unit to start.

[0028] Beneficial effects: When the liquid nitrogen level has reached the preset height but the solenoid valve is still open, it indicates that there may be a malfunction in the solenoid valve or an abnormal control logic. At this time, the alarm unit can be activated to quickly remind the operator to check the problem, prevent the continuous injection of liquid nitrogen from causing overflow, and avoid the safety risks caused by the splashing of cryogenic liquid and freezing of personnel or the leakage of a large amount of cryogenic gas.

[0029] In one alternative embodiment, the cover includes at least two cover plates that can be opened and closed independently, and the through hole is formed on one of the cover plates.

[0030] Beneficial effects: The cover includes at least two independently openable and closable cover plates. When it is necessary to take out or place or observe the workpiece in the cooling box, only the cover plate at the corresponding position can be opened, without having to open the entire cover. This reduces the contact area between liquid nitrogen and the external environment, slows down the evaporation rate of liquid nitrogen, and prevents a large amount of external hot air from entering and affecting the cooling effect.

[0031] In one optional embodiment, the measuring mechanism further includes a protective box located at the top of the connecting rod, and both the detection unit and the controller are located inside the protective box.

[0032] Beneficial effects: By installing the detection unit and controller inside a protective enclosure, the enclosure isolates them from external contaminants such as dust, moisture, and oil, preventing external impurities from adhering to the surface of electronic components and affecting detection accuracy or causing short circuits. Simultaneously, it blocks interference from external light, electromagnetic signals, and other factors, ensuring more accurate liquid level sensing by the detection unit and more stable command transmission by the controller. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of the structure of a liquid nitrogen cooling device in one embodiment provided in this application;

[0035] Figure 2 This is a schematic diagram of the liquid nitrogen cooling device from another perspective in one embodiment provided in this application;

[0036] Figure 3 This is a transparent structural schematic diagram of a liquid nitrogen cooling device in one embodiment provided in this application;

[0037] Figure 4This is a front view of the measuring mechanism in a liquid nitrogen cooling device according to one embodiment provided in this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100. Cooling tank; 110. Receiving cavity; 120. Liquid inlet;

[0040] 200, Cover body; 210, Through hole; 220, Cover plate;

[0041] 300. Measuring mechanism; 310. Floating component; 320. Connecting rod; 330. Protective box. Detailed Implementation

[0042] In related technologies, the ultra-low temperature environment inside the cooling box can cause conventional electronic liquid level sensors to malfunction. Therefore, the industry often relies on manual detection. Operators need to open the cover to observe the liquid level and manually control the injection of liquid nitrogen. This not only poses a risk of frostbite caused by liquid nitrogen splashing, but also easily causes safety hazards due to low temperature gas leakage.

[0043] In the early stages of research and development for this application, to achieve automated detection of the liquid nitrogen level inside the cooling tank, the team initially adopted a technical approach of direct observation through a transparent enclosure. The core design involves using a transparent material (such as special low-temperature resistant glass or transparent polymer material) to construct the main body of the cooling tank, and deploying detection units (such as visual sensors and laser rangefinders) on the outside of the tank. The internal liquid nitrogen level can be directly observed or measured through the transparent walls. The detection units can operate entirely at room temperature, avoiding the impact of ultra-low temperatures on electronic components and theoretically ensuring the stability of detection accuracy. Simultaneously, operators can visually confirm the liquid level status through the transparent enclosure, forming a dual verification mechanism of manual and automated detection.

[0044] However, in actual testing, this solution revealed insurmountable technical limitations. Firstly, the ultra-low temperature environment of liquid nitrogen (-196℃) places stringent demands on the physical properties of transparent materials. Commonly used transparent materials are prone to embrittlement and cracking at extremely low temperatures. Even specially formulated low-temperature resistant materials, after prolonged exposure to the temperature shocks of room temperature and ultra-low temperatures, will exhibit problems such as decreased light transmittance and surface cracking, posing safety hazards. Secondly, transparent materials have weak thermal insulation properties, failing to effectively block heat exchange between the inside and outside of the chamber, leading to accelerated evaporation of liquid nitrogen. This not only increases costs but also causes condensation and frost to form on the inner walls, obstructing vision and making accurate detection and observation impossible. Furthermore, the high cost and limited size of the transparent chamber make it unsuitable for cooling large workpieces. Ultimately, this solution was abandoned due to insufficient practicality, economy, and safety.

[0045] Based on this, the inventors of this application have redesigned the liquid nitrogen cooling device. A float is installed at one end of the connecting rod and placed inside the receiving cavity of the cooling tank, while the other end of the connecting rod extends out of the cooling tank through a through hole. When the liquid nitrogen level in the receiving cavity changes, the float floats with the liquid surface, thereby causing the connecting rod to float up and down. The float senses the changes in the liquid nitrogen level in the receiving cavity in real time and converts these changes into the vertical displacement of the connecting rod. The detection unit measures the height between a preset point on the connecting rod and the cover, and transmits the collected height value to the controller. The controller automatically calculates the liquid nitrogen level height based on a preset algorithm, eliminating the need for manual intervention, improving operational safety, avoiding direct contact between the operator and liquid nitrogen, eliminating the risk of frostbite caused by liquid nitrogen splashing when the cover is opened, and eliminating safety hazards such as asphyxiation caused by low-temperature nitrogen leakage.

[0046] Meanwhile, since the detection unit is located outside the cooling tank, it avoids the effects of ultra-low temperatures, ensuring long-term reliable operation and effectively reducing failure frequency and maintenance costs. Furthermore, the controller relies on precise height data to calculate the liquid level, resulting in higher measurement accuracy and precise control of the liquid nitrogen injection volume, ensuring the stability of the cooling process. Compared to complex cryogenic sensors, the solution of using a measuring mechanism and detection unit to collaboratively measure the liquid level is simpler in structure, lower in manufacturing cost, and easier to install and maintain.

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0048] The following is combined Figures 1 to 4 The embodiments of the present invention are described below.

[0049] According to embodiments of the present invention, on the one hand, such as Figures 1 to 4 As shown, a liquid nitrogen cooling device is provided, including a cooling tank 100, a cover 200, a measuring mechanism 300, a detection unit, and a controller.

[0050] Specifically, the planetary gearbox of a wind turbine is the core component for power transmission. The assembly of the planetary shaft and planetary gears (or bearings) typically uses an interference fit, meaning the diameter of the planetary shaft is slightly larger than the diameter of the mating hole. An interference fit ensures that the components do not slip relative to each other during high-speed operation and under enormous torque, ensuring transmission stability and structural strength. However, direct assembly with an interference fit is extremely difficult. By freezing the planetary shaft with liquid nitrogen, the low temperature causes the shaft to shrink, temporarily reducing the planetary shaft diameter and creating a gap between the shaft and the hole, facilitating easy insertion of the mating parts. After the temperature recovers, the shaft expands, achieving a tight interference fit, thus facilitating the assembly of the planetary gearbox.

[0051] Specifically, such as Figures 1 to 3 As shown, the cooling box 100 is provided with a receiving cavity 110, which is used to contain liquid nitrogen.

[0052] Specifically, such as Figure 1 and Figure 2 As shown, the cover 200 is openable and closable and is installed over the opening of the cooling box 100. The cover 200 has a through hole 210 that penetrates the top and bottom surfaces of the cover 200.

[0053] Specifically, such as Figures 1 to 4 As shown, the measuring mechanism 300 includes a float 310 and a connecting rod 320. The float 310 is mounted on one end of the connecting rod 320 and is located within the receiving cavity 110 of the cooling box 100. The other end of the connecting rod 320 passes through the receiving cavity 110, through the through hole 210, and extends to the outside of the cooling box 100.

[0054] Specifically, such as Figure 1 As shown, a detection unit (not shown in the figure) is mounted on the connecting rod 320 and is installed outside the cooling box 100. The detection unit is used to measure the height between a preset point on the connecting rod 320 and the cover 200.

[0055] Specifically, the controller is electrically connected to the detection unit, and the controller calculates the liquid nitrogen level in the cavity 110 based on the received height value.

[0056] In this liquid nitrogen cooling device, a float 310 is installed at one end of a connecting rod 320 and placed inside the receiving cavity 110 of the cooling tank 100. The other end of the connecting rod 320 extends out of the cooling tank 100 through a through hole 210. When the liquid nitrogen level in the receiving cavity 110 changes, the float 310 floats with the liquid surface, thereby causing the connecting rod 320 to float up and down. The float 310 senses the changes in the liquid nitrogen level in the receiving cavity 110 in real time and converts these changes into the vertical displacement of the connecting rod 320. The detection unit measures the height between a preset point on the connecting rod 320 and the cover 200 and transmits the collected height value to the controller. The controller automatically calculates the liquid nitrogen level height based on a preset algorithm, eliminating the need for manual intervention, improving operational safety, avoiding direct contact between operators and liquid nitrogen, eliminating the risk of frostbite caused by liquid nitrogen splashing when the cover is opened, and eliminating safety hazards such as asphyxiation caused by low-temperature nitrogen leakage.

[0057] Meanwhile, since the detection unit is located outside the cooling tank 100, the effects of ultra-low temperatures on the detection unit are avoided, ensuring long-term reliable operation and effectively reducing the frequency of failures and maintenance costs. Furthermore, the controller relies on precise height data to calculate the liquid level, resulting in higher measurement accuracy and precise control of the liquid nitrogen injection volume, ensuring the stability of the cooling process. The solution of using the measuring mechanism 300 in conjunction with the detection unit to complete the liquid level measurement is simpler in structure, lower in manufacturing cost, and easier to install and maintain compared to complex cryogenic sensors.

[0058] Specifically, the cooling chamber 100 can be configured as a cuboid or cylinder, employing a double-layer insulation structure to reduce liquid nitrogen evaporation loss and maintain a stable ultra-low temperature environment within the cooling chamber 100. In this embodiment, no specific limitations are imposed on the structure of the cooling chamber 100.

[0059] Specifically, the cover 200 can be any structure such as a sealed flip cover or a sliding cover. In this embodiment, the structure of the cover 200 is not specifically limited.

[0060] For example, the cover 200 can be opened and closed by hinge connection or by sliding rail.

[0061] Specifically, the shape design of the through hole 210 needs to be combined with the shape, movement requirements and sealing performance of the connecting rod 320. The through hole 210 can be set as a circular hole, a square hole, an oblong hole, etc. In this embodiment, the shape of the through hole 210 is not specifically limited.

[0062] For example, if the connecting rod 320 is cylindrical and the through hole 210 is circular, the gap between the circular hole and the connecting rod 320 is tighter, reducing liquid nitrogen evaporation while allowing the connecting rod 320 to slide smoothly up and down without jamming. Furthermore, it is simple to manufacture, has a uniform contact area with the circular connecting rod 320, results in less wear, and maintains stable sealing performance even after long-term use.

[0063] Specifically, the shape design of the float 310 needs to meet the requirements of stable buoyancy, sensitive floating with liquid level, and no jamming. The float 310 can be disc-shaped, cylindrical, square, etc. In this embodiment, the shape of the float 310 is not specifically limited.

[0064] Specifically, the float 310 can be detachably mounted on the connecting rod 320, or it can be fixedly mounted on the connecting rod 320, or the float 310 and the connecting rod 320 can be integrally formed. In this embodiment, the connection method between the float 310 and the connecting rod 320 is not specifically limited.

[0065] Specifically, the design of the detection unit needs to meet the requirement of accurately measuring the displacement of the connecting rod 320° under normal temperature conditions. The detection unit can be selected from laser rangefinders, magnetoelectric displacement sensors, infrared distance sensors, etc. In this embodiment, no specific restrictions are placed on the type of detection unit.

[0066] Specifically, the controller can be an existing controller such as a PLC (Programmable Logic Controller), a microcontroller, or a computer control system. In this embodiment, the type of controller is not specifically limited.

[0067] It should be noted that the preset point can be any position on the connecting rod 320. For example, the preset point can be the top position of the connecting rod 320 or the position where the detection unit is installed on the connecting rod 320.

[0068] In one embodiment, such as Figure 1 and Figure 2 As shown, a seal is installed at the mating point between the through hole 210 and the connecting rod 320.

[0069] The evaporation of liquid nitrogen stored in cavity 110 can cause a drop in liquid level, reduced cooling efficiency, and increased costs associated with replenishing liquid nitrogen. By installing a seal at the mating point between the through hole 210 and the connecting rod 320, the seal can reduce the gap between the through hole 210 and the connecting rod 320, preventing liquid nitrogen vapor from leaking out and reducing the entry of hot air from the outside into the chamber. This extends the duration of the cryogenic environment and reduces energy consumption.

[0070] Liquid nitrogen inside the cooling chamber 100 may be conducted outward through the gap between the through hole 210 and the connecting rod 320, causing external detection units, controllers, and other components to condense, freeze, or even be damaged due to material embrittlement at low temperatures. Installing seals can reduce cold leakage, maintain the normal operating temperature of external components, and extend their service life.

[0071] Specifically, if ambient air (containing moisture and dust) from outside the cooling tank 100 enters the cavity 110 through the gap, it will cause frost or ice formation due to the low temperature. The frost or ice will adhere to the wall of the cooling tank 100, the float 310, or the connecting rod 320, which may cause the float 310 to get stuck or the connecting rod 320 to be obstructed, thus affecting the accuracy of liquid level detection.

[0072] Specifically, the sealing element can be a sealing ring, sealing ring, etc. In this embodiment, the type of sealing element is not specifically limited.

[0073] In one embodiment, the seal is configured as thermal insulation cotton.

[0074] The insulation cotton itself has an extremely low thermal conductivity, which can effectively block heat exchange between the inside and outside of the cooling box 100, preventing the low temperature inside the cooling box 100 from transferring cold energy to the outside through the gap between the through hole 210 and the connecting rod 320, and reducing the loss of liquid nitrogen due to heat absorption and evaporation. At the same time, it prevents a large amount of heat from the outside ambient air from entering the cooling box 100, maintaining a stable temperature inside the cooling box 100 and reducing the energy consumption of the cooling system.

[0075] In addition, the coefficient of friction of the heat insulation cotton is much lower than that of materials such as metal and hard rubber. When the connecting rod 320 moves up and down in the through hole 210 with the change of liquid level, the contact resistance between the heat insulation cotton and the connecting rod 320 is relatively small, which can significantly reduce the contact resistance between the two and avoid the jamming and lag caused by excessive friction. This ensures that the connecting rod 320 can respond flexibly and smoothly to the fluctuation of liquid level, thereby ensuring that the detection unit can capture the changes of liquid level in real time and accurately, and maintain the reliability of the measurement data.

[0076] In one embodiment, such as Figure 4 As shown, the floating component 310 is a hollow spherical structure.

[0077] By setting the float 310 to a spherical shape, it can always maintain a stable posture (without tilting or flipping) regardless of changes in liquid level. At the same time, the buoyancy of the sphere is more evenly distributed in the liquid, and it can rise and fall smoothly with the liquid surface even with slight fluctuations in liquid level, avoiding displacement errors of the connecting rod 320 caused by posture swaying and improving detection accuracy.

[0078] By making the float 310 a hollow structure, the weight of the float 310 is reduced. Under the same buoyancy conditions, the sphere can follow the liquid level change (rising or falling) more quickly, reducing hysteresis.

[0079] For example, when the liquid nitrogen level drops slightly, the spherical float 310 can immediately sink with the liquid surface and synchronously feed back to the detection unit through the connecting rod 320, avoiding measurement delays caused by structural inertia.

[0080] In one embodiment, such as Figure 4 As shown, the floating component 310 is made of aluminum.

[0081] Aluminum has a relatively low density compared to other metals. For the same volume, the aluminum float 310 is lighter and can displace liquid nitrogen in a smaller volume to obtain sufficient buoyancy. This avoids sinking or floating unstably due to excessive weight, allowing it to more sensitively follow the rise and fall of the liquid surface and improve the real-time performance of liquid level detection.

[0082] Aluminum is not easily brittle in ultra-low temperature environments and can still maintain a certain degree of ductility and strength. This ensures that the hollow spherical floating component 310 is not easily damaged when repeatedly exposed to liquid nitrogen. In addition, it has a low coefficient of thermal expansion and its size changes little during the alternation of low temperature and room temperature, which can maintain the stability of its floating posture.

[0083] Specifically, a dense oxide film forms on the aluminum surface, which prevents further oxidation and has strong corrosion resistance to inert media such as liquid nitrogen. Long-term contact with liquid nitrogen will not cause rust, corrosion or material deterioration, eliminating the need for additional anti-corrosion treatment and extending service life.

[0084] In one embodiment, such as Figure 1 and Figure 2 As shown, the cooling tank 100 is provided with a liquid inlet 120, which is connected to the receiving cavity 110, and an electrically controlled valve is provided at the liquid inlet 120. The electrically controlled valve is electrically connected to a controller, which is used to control the opening and closing of the electrically controlled valve.

[0085] The controller can automatically control the opening and closing of the electronically controlled valve based on the liquid level height fed back by the detection unit, eliminating the need for manual liquid nitrogen injection and avoiding delays or misjudgments that may be caused by manual operation, thus improving the timeliness and accuracy of liquid level control.

[0086] When the liquid nitrogen level is detected to be lower than the preset value, the controller can quickly instruct the electronically controlled valve to open and replenish the liquid nitrogen; after the liquid level reaches the preset height, it can close the valve in time to ensure that the liquid nitrogen level in the cavity 110 is always maintained within a reasonable range, providing a stable ultra-low temperature cooling environment for the workpiece and ensuring the consistency of the cooling process.

[0087] In addition, the automated liquid nitrogen filling process eliminates the need for personnel to approach the cooling tank 100 for manual operation, further avoiding direct contact between operators and liquid nitrogen and reducing the safety risks of liquid nitrogen splashing causing frostbite or cryogenic gas leakage.

[0088] Specifically, the liquid inlet 120 can be located at the bottom of the cooling tank 100, and the electric control valve can be located outside the cooling tank 100. In this embodiment, the location of the liquid inlet 120 and the electric control valve is not specifically limited.

[0089] In one embodiment, when the liquid nitrogen level in the cavity 110 reaches a preset height, the controller controls the electronically controlled valve to close.

[0090] When the liquid nitrogen level reaches the preset height, the controller promptly closes the electrically controlled valve, limiting the amount of liquid nitrogen injected. This prevents overflow or excessive evaporation due to overfilling, reducing unnecessary material loss and thus lowering operating costs. There is no need for continuous manual monitoring of the liquid level and manual valve closure; the controller automatically closes the valve based on the preset height, further freeing up manpower, reducing the labor intensity of manual operation, and making the automated operation of the entire liquid nitrogen cooling system more efficient and reliable.

[0091] By closing the electrically controlled valve when the liquid level reaches a preset height, the liquid nitrogen level in the cavity 110 can be kept stable within the set range, avoiding the cooling effect caused by excessively high or low liquid levels. This ensures that the workpiece completes the cooling process in a uniform and stable ultra-low temperature environment, improving the consistency of product quality.

[0092] Specifically, excessive liquid nitrogen filling may cause an abnormal increase in pressure within the cooling tank. The controller shuts off the electrically controlled valve when the liquid level reaches the target level, effectively preventing this situation, reducing damage to the equipment caused by overpressure or excessive corrosion, and extending the lifespan of the device.

[0093] In one embodiment, the liquid nitrogen cooling device further includes an alarm unit (not shown), wherein the alarm unit is electrically connected to the controller. When the liquid nitrogen level in the receiving cavity 110 reaches a preset height, and the electrically controlled valve is still in the open state, the controller controls the alarm unit to be activated.

[0094] When the liquid nitrogen level has reached the preset height but the solenoid valve is still open, it indicates that there may be a malfunction in the solenoid valve or an abnormal control logic. At this time, the alarm unit will be activated to quickly remind the operator to check the problem, prevent the continuous injection of liquid nitrogen from causing overflow, and avoid the safety risks caused by the splashing of cryogenic liquid and freezing of personnel or the leakage of a large amount of cryogenic gas.

[0095] In one embodiment, such as Figures 1 to 3 As shown, the cover 200 includes at least two cover plates 220 that can be opened and closed independently, and a through hole 210 is formed on one of the cover plates 220.

[0096] The cover 200 includes at least two independently openable and closable cover plates 220. When it is necessary to take out or place or observe the workpiece in the cooling box 100, only the cover plate 220 at the corresponding position can be opened, without having to open the entire cover 200. This reduces the contact area between liquid nitrogen and the external environment, slows down the evaporation rate of liquid nitrogen, and prevents a large amount of external hot air from entering and affecting the cooling effect.

[0097] The cover plate 220 where the through hole 210 is located can be kept closed independently and opened only when pipeline connection or inspection operation is required through the through hole 210. When the cover plate 220 on the cover body 200 needs to be opened, the cover plate 220 where the through hole 210 is located can still be kept closed to detect the liquid nitrogen level in the cavity 110.

[0098] Specifically, two cover plates 220, three cover plates 220, etc. can be provided on the cover body 200. In this embodiment of the application, the number of cover plates 220 is not specifically limited.

[0099] For example, two cover plates 220 are provided on the cover body 200. The two cover plates 220 are arranged opposite to each other and are connected by a hinge to realize independent opening and closing.

[0100] In one embodiment, the measuring mechanism 300 further includes a protective box 330, wherein the protective box 330 is mounted on the top of the connecting rod 320, and the detection unit and the controller are both mounted on the protective box 330.

[0101] By installing the detection unit and controller inside the protective housing 330, the housing isolates them from external contaminants such as dust, moisture, and oil, preventing external impurities from adhering to the surface of electronic components and affecting detection accuracy or causing short circuits. Simultaneously, it blocks interference from external light, electromagnetic signals, and other factors, ensuring more accurate liquid level sensing by the detection unit and more stable command transmission by the controller.

[0102] Positioning the protective box 330 at the top of the connecting rod 320 allows for a reasonable distribution of the rod's length, ensuring that a sufficient portion of the connecting rod extends into the receiving cavity 110 of the cooling tank 100, effectively connecting with the float 310. When the liquid nitrogen level changes, the vertical displacement generated by the float 310 driving the connecting rod 320 is transmitted completely to the top of the protective box 330 via the sufficiently long connecting rod, enabling the detection unit within the protective box 330 to accurately detect this change. If the protective box 330 is positioned too low, it may compress the effective length of the connecting rod 320 extending into the receiving cavity 110, resulting in large changes in the liquid level not being fully reflected by the displacement of the connecting rod 320, thus affecting the sensitivity and accuracy of the liquid level feedback.

[0103] The working principle of the liquid nitrogen cooling device in this embodiment is described as follows:

[0104] When the liquid nitrogen level in the cavity 110 changes, the float 310 floats with the liquid surface, which in turn causes the connecting rod 320 to float up and down. The float 310 senses the changes in the liquid nitrogen level in the cavity 110 in real time and converts the changes in the liquid nitrogen level into the vertical displacement of the connecting rod 320. The detection unit measures the height between a preset point on the connecting rod 320 and the cover 200 and transmits the collected height value to the controller. The controller automatically calculates the liquid nitrogen level height based on a preset algorithm.

[0105] When the liquid level is detected to be below the minimum threshold, such as below 70cm, the controller instructs the electronically controlled valve to open and replenish liquid nitrogen into the cavity 110. When the liquid level rises to the preset height (maximum threshold), such as 80cm, the controller instructs the electronically controlled valve to close and stop replenishing liquid, ensuring that the liquid level is stable in the optimal cooling range and avoiding excessive or insufficient liquid from affecting the cooling effect.

[0106] If an abnormality occurs where "the liquid level has reached the preset height (maximum threshold) but the electrically controlled valve is still open," the controller will immediately trigger the alarm unit (such as an audible and visual alarm) to remind operators to investigate in time and prevent risks such as low-temperature freezing and equipment overpressure caused by liquid nitrogen overflow.

[0107] The terms "upper" and "lower" are used to describe the relative positions of the various structures in the accompanying drawings. They are only for clarity of description and are not intended to limit the scope of implementation of this application. Any changes or adjustments to the relative positions without substantially altering the technical content shall also be considered within the scope of implementation of this application.

[0108] It should be noted that, in this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0109] Furthermore, in this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0110] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A liquid nitrogen cooling device, characterized in that, include: Cooling tank (100) has a cavity (110) for containing liquid nitrogen; A cover (200) is provided at the opening of the cooling box (100), and a through hole (210) is provided on the cover (200) through the top and bottom surfaces of the cover (200). The measuring mechanism (300) includes a float (310) and a connecting rod (320). The float (310) is disposed at one end of the connecting rod (320) and located in the receiving cavity (110). The other end of the connecting rod (320) passes through the through hole (210) and extends to the outside of the cooling box (100). A detection unit is provided on the connecting rod (320) and located outside the cooling box (100). The detection unit is used to measure the height value between a preset point on the connecting rod (320) and the cover (200). A controller, electrically connected to the detection unit, calculates the liquid nitrogen level in the containment cavity (110) based on the received height value.

2. The liquid nitrogen cooling device according to claim 1, characterized in that, A sealing element is provided at the mating point between the through hole (210) and the connecting rod (320).

3. The liquid nitrogen cooling device according to claim 2, characterized in that, The seal is configured as thermal insulation cotton.

4. The liquid nitrogen cooling device according to claim 1, characterized in that, The floating component (310) is a hollow spherical structure.

5. The liquid nitrogen cooling device according to claim 4, characterized in that, The floating component (310) is made of aluminum.

6. The liquid nitrogen cooling device according to any one of claims 1 to 5, characterized in that, The cooling tank (100) is provided with a liquid inlet (120) communicating with the receiving cavity (110), and an electric control valve is provided at the liquid inlet (120); The electrically controlled valve is electrically connected to the controller, which is used to control the opening and closing of the electrically controlled valve.

7. The liquid nitrogen cooling device according to claim 6, characterized in that, When the liquid nitrogen level in the cavity (110) reaches a preset height, the controller controls the electronically controlled valve to close.

8. The liquid nitrogen cooling device according to claim 7, characterized in that, The liquid nitrogen cooling device also includes an alarm unit, which is electrically connected to the controller. When the liquid nitrogen level in the cavity (110) reaches a preset height and the electronically controlled valve is in the open state, the controller controls the alarm unit to start.

9. The liquid nitrogen cooling device according to claim 6, characterized in that, The cover (200) includes at least two cover plates (220) that can be opened and closed independently, and the through hole (210) is formed on one of the cover plates (220).

10. The liquid nitrogen cooling device according to claim 6, characterized in that, The measuring mechanism (300) also includes a protective box (330), which is located at the top of the connecting rod (320). The detection unit and the controller are both located inside the protective box (330).

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