Zero-loss liquid nitrogen tank, and pressure calculation method and manufacturing method

Abstract

A zero-loss liquid nitrogen tank, a pressure calculation method and a manufacturing method. The method comprises: setting an enclosed space in a liquid nitrogen tank, and filling the enclosed space with a certain amount of liquid nitrogen; S1: at a given temperature, calculating the actual pressure of the enclosed space in the liquid nitrogen tank; S2: on the basis of the proportion of the liquid nitrogen, performing pressure correction to obtain a pressure correction coefficient; and S3: using the pressure correction coefficient to calculate a target pressure. An appropriate amount of liquid nitrogen is filled according to the calculated pressure that the tank body can withstand, thereby achieving the optimal effect while ensuring safety, preventing poor effects caused by underfilling and hidden dangers caused by overfilling, and greatly reducing the use cost of liquid nitrogen.

Description

A zero-consumption liquid nitrogen tank, pressure calculation method and manufacturing method Technical Field

[0001] This invention relates to the field of sample storage technology, and in particular to a zero-consumption liquid nitrogen tank, a pressure calculation method, and a manufacturing method. Background Technology

[0002] In the field of biological sample storage, cryogenic storage equipment is used to store biological samples such as blood samples, vaccines, and bacterial and viral strains at low temperatures, so that the samples can be kept alive at low temperatures.

[0003] Currently, liquid nitrogen is used for cooling. However, each liquid nitrogen tank has a large daily demand for liquid nitrogen. The consumed liquid nitrogen vaporizes and dissipates, and this wasted liquid nitrogen cannot be recycled, which increases costs significantly.

[0004] In some sealed liquid nitrogen cylinders, filling too little liquid nitrogen may result in poor performance, while filling too much may pose a potential danger of excessive pressure. To address this, the inventors designed a zero-consumption liquid nitrogen tank, a pressure calculation method, and a manufacturing method. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to provide a method for calculating the pressure of a liquid nitrogen tank, which solves the problem of liquid nitrogen vaporization and escape from existing liquid nitrogen tanks, resulting in wasted liquid nitrogen that cannot be recycled and significantly increases costs. Furthermore, the tank is lightweight and easy to use. The corresponding pressure calculation method can determine the optimal amount of liquid nitrogen to fill the liquid nitrogen bottle, preventing the problems of insufficient filling leading to poor results and excessive filling posing potential risks.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for calculating the pressure of a liquid nitrogen tank, which includes setting up a closed space inside a liquid nitrogen tank and filling the space with a certain amount of liquid nitrogen;

[0009] S1: Calculate the actual pressure in the enclosed space inside the liquid nitrogen tank at a given temperature;

[0010] S2: Based on the proportion of liquid nitrogen, pressure correction is performed to obtain the pressure correction coefficient;

[0011] S3: Calculate the target pressure using the pressure correction coefficient.

[0012] As a preferred embodiment of the liquid nitrogen tank pressure calculation method of the present invention, wherein: the vapor pressure function is used in S1: ;

[0013] Where P represents vapor pressure; Pc represents critical pressure; Ni and ti represent constants and exponents of liquid nitrogen; Tc represents critical temperature of liquid nitrogen; T represents absolute temperature; and Θ is a temperature correction factor.

[0014] As a preferred embodiment of the liquid nitrogen tank pressure calculation method of the present invention, the calculation temperature correction coefficient is as follows: .

[0015] As a preferred embodiment of the liquid nitrogen tank pressure calculation method of the present invention, the target pressure calculation formula is as follows: Where Pi represents pressure and k represents the pressure correction factor.

[0016] As a preferred embodiment of the liquid nitrogen tank pressure calculation method of the present invention, the parameters Ni and ti of liquid nitrogen can be obtained through experimental data.

[0017] As a preferred embodiment of the liquid nitrogen tank pressure calculation method of the present invention, the pressure correction coefficient k is a value obtained based on the pressure at different temperatures after different liquid nitrogen ratios.

[0018] This invention also provides a zero-consumption liquid nitrogen tank, which can hold liquid nitrogen in the tank. When the temperature inside the tank rises, the liquid nitrogen vaporizes, and when the temperature drops, the nitrogen vapor liquefies again, thus circulating the liquid nitrogen. This allows for one-time filling and lifetime use, saving a large amount of liquid nitrogen and significantly reducing costs. The tank is small in size and cools down by conducting heat to the outside, making it applicable to various usage scenarios. It is convenient to use and can be recycled.

[0019] To achieve the above-mentioned technical effects, the present invention also provides the following technical solution: including a tank, a sealed area is formed inside the tank, and liquid nitrogen is filled in the sealed area. The amount of liquid nitrogen filled is based on the pressure that the tank can withstand, obtained by the liquid nitrogen tank pressure calculation method.

[0020] As a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the tank body is provided with a refrigeration circulation component, which can cool and liquefy the vaporized nitrogen in the tank body, and the refrigeration circulation component is provided with a heat preservation component, which can keep the refrigeration circulation component warm.

[0021] In a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the refrigeration cycle assembly includes a refrigeration component and a liquefaction component; the liquefaction component is connected to the refrigeration component, the refrigeration component can refrigerate the liquefaction component, and the liquefaction component can liquefy nitrogen.

[0022] In a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the liquefaction component is disposed at the upper end of the tank body and is disposed within the insulation component.

[0023] As a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the insulation component includes a vacuum insulation layer; the interior of the vacuum insulation layer is a vacuum, and the vacuum insulation layer is arranged vertically on the outer side of the upper end of the tank body.

[0024] As a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the insulation component further includes an extraction component; the extraction component is disposed on the vacuum insulation layer, and the extraction component can extract the gas inside the vacuum insulation layer.

[0025] As a preferred embodiment of the zero-consumption liquid nitrogen tank of the present invention, the tank body is further provided with a sealing component, through which liquid nitrogen can enter the interior of the tank body, and the sealing component can seal the tank body.

[0026] The present invention also provides a method for manufacturing a zero-consumption liquid nitrogen tank, which enables the manufacturing process of a zero-consumption liquid nitrogen tank and ensures the sealing and stability of the liquid nitrogen tank.

[0027] To facilitate the manufacturing process of liquid nitrogen tanks, this invention also provides a method for manufacturing a zero-consumption liquid nitrogen tank, including a zero-consumption liquid nitrogen tank and a manufacturing method comprising the following steps:

[0028] D1: The tank body is welded and sealed;

[0029] D2: The upper end of the tank is sealed with a liquefaction component, which is connected to the refrigeration component;

[0030] D3: The vacuum insulation layer is placed over the upper part of the tank and the liquefied components are wrapped.

[0031] D4: Use the extraction component to extract the gas inside the vacuum insulation layer, so that the vacuum insulation layer can keep the liquefied component cold.

[0032] D5: Open the sealing parts and inject one-quarter of the liquid nitrogen into the tank;

[0033] D6: Seal the sealing component to the tank body.

[0034] The beneficial effects of the liquid nitrogen tank pressure calculation method of the present invention are as follows: by filling an appropriate amount of liquid nitrogen evenly according to the calculated pressure that the tank can withstand, the optimal effect is achieved under the condition of ensuring safety, and the problems of insufficient filling resulting in poor effect and excessive filling posing hidden dangers are prevented.

[0035] The beneficial effects of the zero-consumption liquid nitrogen tank of this invention are as follows: 1. The tank contains liquid nitrogen. When the temperature inside the tank rises, the liquid nitrogen vaporizes. When the temperature drops, the nitrogen vapor liquefies again, thus circulating the liquid nitrogen. This allows for one-time filling and lifetime use, saving a significant amount of liquid nitrogen and greatly reducing costs. 2. The tank is small in size and cools by conducting heat to the outside, making it suitable for various applications. It is easy to access and reusable. 3. The liquefaction component has a rear end that can connect to an external cooling component for liquefaction. The front end of the liquefaction component is finned to increase the contact area with the gas inside the tank, resulting in a faster cooling rate. It also facilitates the downward flow of gaseous liquid nitrogen after low-temperature liquefaction. 4. A vacuum insulation layer is provided around the upper end of the tank to prevent the cooling from the liquefaction component from diffusing outwards from the sides, reducing energy consumption. 5. A sealing component is provided at the bottom of the tank. When the sealing component is open, liquid nitrogen can be injected. After injection, the tank is sealed to ensure its airtightness and stability.

[0036] The beneficial effects of the zero-consumption liquid nitrogen tank manufacturing method of the present invention are as follows: This manufacturing method can seal the tank body, use the extraction component to extract the gas inside the vacuum insulation layer, so that the vacuum insulation layer keeps the liquefied component cold; inject one-quarter of the liquid nitrogen into the tank body according to the tank body volume, and seal the tank body with the sealing component, thus ensuring the sealing and stability of the liquid nitrogen tank, and realizing one-time liquid filling and lifetime use. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0038] Figure 1 shows the experimental data for the liquid nitrogen tank pressure calculation method.

[0039] Figure 2 shows the pressure calculation curve of the liquid nitrogen tank pressure calculation method.

[0040] Figure 3 shows the steps of the liquid nitrogen tank pressure calculation method.

[0041] Figure 4 is a three-dimensional schematic diagram of a zero-consumption liquid nitrogen tank.

[0042] Figure 5 is a cross-sectional view of the zero-consumption liquid nitrogen tank.

[0043] Figure 6 is an enlarged view of point F1 of the zero-consumption liquid nitrogen tank in Figure 5.

[0044] Figure 7 is an enlarged view of point F2 of the zero-consumption liquid nitrogen tank in Figure 5.

[0045] Figure 8 is a cross-sectional view of the overall structure of the zero-consumption liquid nitrogen tank.

[0046] Figure 9 is a schematic diagram of the steps involved in making a zero-consumption liquid nitrogen tank.

[0047] Reference numerals: Tank body, 1; Refrigeration cycle assembly, 2; Insulation assembly, 3; Refrigeration component, 21; Liquefaction component, 22; Vacuum insulation layer, 31; Extraction component, 32; Sealing component, 4; Detailed Implementation

[0048] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0049] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0050] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments. Example 1

[0051] Referring to Figures 1-3, the first embodiment of the present invention provides a method for calculating the pressure of a liquid nitrogen tank, which includes setting up a closed space inside a liquid nitrogen tank and filling the space with a fixed amount of liquid nitrogen;

[0052] S1: Calculate the actual pressure in the enclosed space inside the liquid nitrogen tank at a given temperature;

[0053] S2: Based on the proportion of liquid nitrogen, pressure correction is performed to obtain the pressure correction coefficient;

[0054] S3: Calculate the target pressure using the pressure correction coefficient.

[0055] Ideally, a temperature is set, and the actual pressure in the enclosed space inside the liquid nitrogen tank is calculated. Based on the proportion of liquid nitrogen in the liquid nitrogen tank, a pressure correction is performed, thus obtaining a pressure correction coefficient. Through the above operations, a formula for calculating the new pressure, i.e. the target pressure, is obtained, realizing the calculation of the target pressure. This calculation method can determine how much liquid nitrogen to put in different liquid nitrogen tanks to achieve the optimal effect.

[0056] It should be noted that we need to combine the proportion of liquid nitrogen in the confined space with the pressure at different temperatures to formulate a pressure calculation formula. We can assume that the proportion of liquid nitrogen in the confined space affects the vapor pressure, and we need to ensure that the pressure does not exceed a safe threshold at any given temperature.

[0057] Furthermore, S1 uses the vapor pressure function: ;

[0058] Where P represents vapor pressure; Pc represents critical pressure; Ni and ti represent constants and exponents of liquid nitrogen; Tc represents critical temperature of liquid nitrogen; T represents absolute temperature; and Θ is a temperature correction factor.

[0059] Ideally, using the vapor pressure function, we can calculate the actual pressure at a given temperature. For example, the pressure at +20°C, -135°C, and -147°C;

[0060] Further, calculate the temperature correction factor: .

[0061] Furthermore, the formula for calculating the target pressure is: Where Pi represents pressure and k represents the pressure correction factor.

[0062] Furthermore, the parameters Ni and Ti of liquid nitrogen can be obtained through experimental data.

[0063] Furthermore, the pressure correction factor k is a value derived from the pressure at different temperatures with different liquid nitrogen ratios.

[0064] It should be noted that the pressure correction factor k is a value obtained based on different liquid nitrogen ratios. The pressure correction factor is different at different temperatures and is obtained through experiments.

[0065] It should be noted that this is based on the known conditions;

[0066] The critical temperature of liquid nitrogen, Tc, is -146.958℃ (equivalent to 126.2K in Kelvin).

[0067] The critical pressure of liquid nitrogen, Pc, is 3.3958 MPa.

[0068] The parameters of liquid nitrogen, Ni​,ti​: experimentally obtained N1​=1, t1​=0.3;

[0069] The pressure calculation process of the enclosed space when it is stable at +20℃, -135℃, and -147℃ is as follows. The enclosed space is filled with liquid nitrogen, which accounts for 23% of the volume, and is sealed at a steady state of -190℃ (83.15K). The density value is 188 Kg / m³.

[0070] It should be noted that the pressure calculation process at +20℃ is as follows:

[0071] The calculation process of the pressure in a closed space when it is stable at +20℃. The closed space is filled with liquid nitrogen, which accounts for 23% of the volume, and is sealed at a steady state of -190℃ (83.15K); the density value is 188 Kg / m³.

[0072] The parameters Ni and ti of liquid nitrogen were obtained through experimental calculations, with N1 = 1 and t1 = 0.3.

[0073] Adjustment coefficient k: k = 4.077, obtained through experiments;

[0074] Temperature: T = 293.15 K (+20℃)

[0075] Calculate Θ:

[0076]

[0077] Calculate the vapor pressure P:

[0078]

[0079]

[0080]

[0081]

[0082] Calculate pressure Pi:

[0083] .

[0084] It should be noted that the pressure at -135℃ is calculated as follows:

[0085] The critical temperature of liquid nitrogen, Tc, is -146.958℃ (equivalent to 126.2K in Kelvin).

[0086] The critical pressure of liquid nitrogen, Pc, is 3.3958 MPa.

[0087] Temperature: T=138.15 K

[0088] The parameters Ni and ti of liquid nitrogen were obtained through experimental calculations, with N1 = 1 and t1 = 0.3.

[0089] K=0.769, obtained through experiments;

[0090] Calculate Θ:

[0091]

[0092] Calculate the vapor pressure P:

[0093]

[0094]

[0095] ;

[0096]

[0097] Calculate pressure Pi:

[0098] ;

[0099]

[0100] Calculation of safe pressure at -147℃

[0101] The critical temperature of liquid nitrogen, Tc, is -146.958℃ (equivalent to 126.2K in Kelvin).

[0102] The critical pressure of liquid nitrogen, Pc, is 3.3958 MPa.

[0103] Temperature: T=126.15 K (-147℃)

[0104] The parameters for liquid nitrogen are Ni​, ti​, constant N1​=1, and exponent t1​=0.3​.

[0105] K=0.884, obtained through experiments;

[0106] Calculate Θ:

[0107] =0.0004 at the critical point;

[0108] Calculate pressure Pi:

[0109]

[0110] ≈ ≈1.00006

[0111] P= =0.130006

[0112] Pi = ≈3.002MPa ≈3 MPa

[0113] Based on the above calculations, it is demonstrated how to use the physical properties of liquid nitrogen and environmental conditions to estimate the pressure inside a container at a specific temperature and with a certain percentage of liquid nitrogen.

[0114] It should be noted that, according to calculations, when the tank contains about one-quarter of its volume of liquid nitrogen, the pressure generated by vaporization has the least impact on the strength and service life of the tank, and will not pose a safety hazard.

[0115] In summary, the liquid nitrogen tank pressure calculation method of the present invention calculates the pressure that the tank can withstand and fills it with an appropriate amount of liquid nitrogen in a balanced manner, thereby achieving the optimal effect while ensuring safety and preventing the problems of insufficient filling resulting in poor effect and excessive filling posing potential hazards.

[0116] Example 2

[0117] Referring to Figures 3-8, this is the second embodiment of the present invention. Based on embodiment 1, a zero-consumption liquid nitrogen tank is further provided, including a tank body 1, a sealed area formed inside the tank body 1, and liquid nitrogen filled in the sealed area. The amount of liquid nitrogen filled is the pressure that the tank body 1 can withstand, obtained by the liquid nitrogen tank pressure calculation method according to any one of claims 1-6.

[0118] Preferably, liquid nitrogen is installed inside the container 1 to provide ultra-low temperature cooling for the container 1, and the sample can be cryogenically frozen through the container 1.

[0119] Furthermore, a refrigeration circulation component 2 is provided on the tank body 1, which can cool and liquefy the vaporized nitrogen in the tank body 1. An insulation component 3 is provided on the refrigeration circulation component 2, which can keep the refrigeration circulation component 2 warm.

[0120] Preferably, liquid nitrogen can be vaporized in tank 1 and liquefied using refrigeration cycle component 2. The liquid nitrogen is circulated and vaporized inside tank 1 and then liquefied again by refrigeration cycle component 2, thus achieving the goal of using liquid nitrogen only once and then circulating it, which greatly reduces the cost of using liquid nitrogen.

[0121] Furthermore, the refrigeration cycle assembly 2 includes a refrigeration component 21 and a liquefaction component 22; the liquefaction component 22 is connected to the refrigeration component 21, the refrigeration component 21 can refrigerate the liquefaction component 22, and the liquefaction component 22 can liquefy nitrogen.

[0122] Preferably, the refrigeration component 21 is a Stirling refrigerator, which can circulate and refrigerate the liquefaction component 22. The liquefaction component 22 can lower the temperature of the vaporized nitrogen, thus converting the nitrogen into liquid nitrogen.

[0123] Preferably, the bottom of the liquefaction component 22 is finned, which can increase the contact area between nitrogen and the liquefaction component 22, making the liquefaction speed faster.

[0124] Furthermore, the liquefaction component 22 is located at the upper end of the tank body 1 and is housed within the insulation component 3.

[0125] Preferably, by setting the liquefaction component 22 at the upper end of the tank 1, it is convenient to liquefy the rising nitrogen gas, and the liquefied liquid nitrogen will flow back into the tank 1 after liquefaction, thus realizing the cycle conversion.

[0126] Furthermore, the insulation component 3 includes a vacuum insulation layer 31; the interior of the vacuum insulation layer 31 is a vacuum, and the vacuum insulation layer 31 is arranged vertically on the outer side of the upper end of the tank body 1.

[0127] Preferably, the vacuum insulation layer 31 can prevent the cooling from the liquefied component 22 inside the tank from diffusing to the outside from the side, thus reducing energy consumption.

[0128] Furthermore, the insulation component 3 also includes an extraction component 32; the extraction component 32 is disposed on the vacuum insulation layer 31, and the extraction component 32 can extract the gas inside the vacuum insulation layer 31.

[0129] Preferably, by setting the extraction component 32, the gas inside the vacuum insulation layer 31 can be evacuated, so that the vacuum insulation layer 31 is kept under vacuum.

[0130] Furthermore, a sealing element 4 is also provided on the tank body 1, through which liquid nitrogen can enter the interior of the tank body 1, and the sealing element 4 can seal the tank body 1.

[0131] Preferably, the tank body 1 can be sealed by the sealing element 4; when the sealing element 4 is open, liquid nitrogen can be injected into the tank body 1. After the liquid nitrogen is injected, the sealing element 4 seals the tank body 1 and it is in an unremovable state.

[0132] In summary, this invention uses a tank 1 to hold liquid nitrogen. The temperature inside the tank rises, causing the liquid nitrogen to vaporize. The nitrogen is then liquefied using a refrigeration cycle component 2, allowing for liquid nitrogen circulation. This enables a single filling and lifetime use, saving a significant amount of liquid nitrogen and greatly reducing costs. The tank 1 is small in size and cools by conducting heat to the outside, making it suitable for various applications. It is easy to access and reusable. The rear end of the liquefaction component 22 can be connected to the refrigeration component 21. The front end of the liquefaction component 22 is finned, increasing the contact area with the gas inside the tank for faster cooling and facilitating the downward flow of the liquefied gaseous nitrogen. A vacuum insulation layer 31 is provided around the upper end of the tank 1 to prevent the cooling from the liquefaction component 22 from diffusing outwards from the sides, reducing energy consumption. Liquid nitrogen is injected into the tank through the lower inlet and sealed by a sealing component 4 supported by sealing material, ensuring the airtightness and stability of the tank 1.

[0133] Example 3

[0134] Referring to Figure 9, which illustrates the third embodiment of the present invention, based on Embodiments 1 and 2, a method for manufacturing a zero-consumption liquid nitrogen tank is further provided, comprising the following manufacturing method.

[0135] D1: Tank 1 is welded and sealed;

[0136] D2: The upper end of the tank 1 is sealed with a liquefaction component 22, which is connected to the refrigeration component 21.

[0137] D3: The vacuum insulation layer 31 is fitted onto the upper part of the tank body 1 and wraps the liquefied component 22.

[0138] D4: Use the extraction component 32 to extract the gas inside the vacuum insulation layer 31, so that the vacuum insulation layer 31 can keep the liquefied component 22 cold.

[0139] D5: Open the sealing part 4 and inject one-quarter of the liquid nitrogen into the tank 1;

[0140] D6: Seal the sealing component 4 to the tank body 1.

[0141] In summary, this manufacturing method allows the tank 1 to be sealed, and the gas inside the vacuum insulation layer 31 is extracted using the extraction component 32, so that the vacuum insulation layer 31 keeps the liquefied component 22 cold. One-quarter of the liquid nitrogen is injected into the tank according to its volume, and the sealing component 4 is used to seal the tank 1, ensuring the sealing and stability of the liquid nitrogen tank, and enabling it to be used for a lifetime after a single filling.

[0142] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0143] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0144] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0145] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for calculating the pressure of a liquid nitrogen tank, characterized in that: Set up a closed space inside a liquid nitrogen tank, and fill this space with a fixed amount of liquid nitrogen; S1: Calculate the actual pressure in the enclosed space inside the liquid nitrogen tank at a given temperature; S2: Based on the liquid nitrogen ratio, pressure correction is performed to obtain the pressure correction coefficient; S3: Calculate the target pressure using the pressure correction coefficient.

2. The method for calculating the pressure of a liquid nitrogen tank as described in claim 1, characterized in that: S1 uses the vapor pressure function: ; Where P represents vapor pressure; Pc represents the critical pressure; Ni and ti represent the constant and exponent of liquid nitrogen; Tc represents the critical temperature of liquid nitrogen; T represents the absolute temperature; and Θ is the temperature correction factor.

3. The method for calculating the pressure of a liquid nitrogen tank as described in claim 2, characterized in that: Calculate the temperature correction factor: .

4. The method for calculating the pressure of a liquid nitrogen tank as described in claim 3, characterized in that: Target pressure calculation formula: ; Where Pi represents pressure; k represents the pressure correction factor.

5. The method for calculating the pressure of a liquid nitrogen tank as described in claim 4, characterized in that: The parameters Ni and Ti of liquid nitrogen can be obtained through experimental data.

6. The method for calculating the pressure of a liquid nitrogen tank as described in claim 4, characterized in that: The pressure correction factor k is a value derived from the pressure at different temperatures with different liquid nitrogen ratios.

7. A zero-consumption liquid nitrogen tank, characterized in that: The container includes a tank (1), a sealed area is formed inside the tank (1), and liquid nitrogen is filled in the sealed area. The amount of liquid nitrogen filled is the pressure that the tank (1) can withstand, as calculated by the liquid nitrogen tank pressure calculation method according to any one of claims 1-6.

8. The zero-consumption liquid nitrogen tank as described in claim 7, characterized in that: The tank (1) is provided with a refrigeration circulation component (2), which can cool and liquefy the vaporized nitrogen in the tank (1). The refrigeration circulation component (2) is provided with a heat preservation component (3), which can keep the refrigeration circulation component (2) warm.

9. The zero-consumption liquid nitrogen tank as described in claim 8, characterized in that: The refrigeration cycle assembly (2) includes a refrigeration component (21) and a liquefaction component (22); the liquefaction component (22) is connected to the refrigeration component (21), the refrigeration component (21) can refrigerate the liquefaction component (22), and the liquefaction component (22) can liquefy nitrogen.

10. The zero-consumption liquid nitrogen tank as described in claim 9, characterized in that: The liquefaction component (22) is located at the upper end of the tank body (1) and is located inside the insulation component (3).

11. The zero-consumption liquid nitrogen tank as described in claim 10, characterized in that: The insulation component (3) includes a vacuum insulation layer (31); the vacuum insulation layer (31) is a vacuum inside, and the vacuum insulation layer (31) is arranged on the outer side of the upper end of the tank body (1) in a vertical circumference.

12. The zero-consumption liquid nitrogen tank as described in claim 11, characterized in that: The insulation component (3) also includes an extraction component (32); the extraction component (32) is disposed on the vacuum insulation layer (31), and the extraction component (32) can extract the gas inside the vacuum insulation layer (31).

13. The zero-consumption liquid nitrogen tank as described in claim 12, characterized in that: The tank (1) is also provided with a sealing component (4), through which liquid nitrogen can enter the tank (1) and the sealing component (4) can seal the tank (1).

14. A method for manufacturing a zero-consumption liquid nitrogen tank, characterized in that: The zero-consumption liquid nitrogen tank as described in claim 13, and a manufacturing method comprising the following: D1: The tank body (1) is welded and sealed; D2: The upper end of the tank (1) is sealed and connected to the liquefaction component (22), and the liquefaction component (22) is connected to the refrigeration component (21); D3: The vacuum insulation layer (31) is placed on the upper part of the tank (1) and the liquefied component (22) is wrapped. D4: Use the extraction component (32) to extract the gas inside the vacuum insulation layer (31) so that the vacuum insulation layer (31) can keep the liquefied component (22) cold; D5: Open the sealing part (4) and inject one-quarter of the liquid nitrogen into the tank (1); D6: Seal the plug (4) to the tank (1).

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