Helium isothermal adsorption measuring and calculating method based on magnetic suspension balance

Abstract

The invention discloses a helium isothermal adsorption measuring and calculating method based on a magnetic suspension balance, which comprises the following steps: vacuumizing a magnetic suspension balance sample cabin for storing a sample at a preset temperature for a preset time, and obtaining a first mass of the sample after the temperature of an indoor environment; acquiring the second mass and volume of the sample frame, setting a plurality of adsorption temperature points, and acquiring the readings of the magnetic suspension balance corresponding to different adsorption pressure points at each adsorption temperature point and the free phase helium density in the sample cabin; drawing a linear relation graph of each adsorption temperature point according to the reading and the free phase helium density, and calculating the slope; fitting a plurality of adsorption temperature points, the slope, the first mass, the volume and an ideal gas constant to obtain the unit mass skeleton volume of the sample; calculating the helium adsorption capacity by combining the first mass, the second mass, the volume, the reading, the free phase helium density and the atomic mass of helium, drawing a helium isothermal adsorption curve of each adsorption temperature point, and performing fitting to obtain the maximum Langmuir adsorption capacity and Langmuir pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular simulation, and in particular to, but is not limited to, a helium isothermal adsorption measurement method based on a magnetic suspension balance. Background Art

[0002] Due to its monatomic structure, small atomic radius, and low polarizability, helium has one of the lowest adsorption capacities in nature. Currently, in shale gas and coalbed methane resource evaluation and CO2 storage research, researchers typically conduct isothermal adsorption experiments on coal and organic-rich shales based on the assumption that helium has no adsorption capacity. These experiments measure the adsorption capacity of gases such as methane and CO2 to assess shale gas and coalbed methane resources or CO2 storage capacity. Although the intermolecular forces between helium and other molecules (such as van der Waals forces) are very weak, they are not completely zero. Theoretically, helium has adsorption capacity, and this capacity is significantly enhanced under high pressure. This has been confirmed by molecular simulation studies. Therefore, traditional isothermal adsorption experimental methods based on the assumption of zero helium adsorption inevitably have limitations in accuracy. Establishing accurate helium adsorption measurement methods is crucial for shale gas and coalbed methane resource evaluation and CO2 storage effectiveness assessment.

[0003] Furthermore, due to its unique physical properties, helium is widely used in fields such as semiconductors and national defense, making it a scarce strategic resource for the nation. Establishing a helium reservoir theory tailored to my country's geological conditions, promoting further helium exploration, and increasing self-sufficiency in helium resources are urgent national needs. Currently, all industrially utilized helium resources come from the extraction of underground helium-rich natural gas. Establishing accurate helium adsorption measurement methods and evaluating the adsorption characteristics of helium under high-pressure underground conditions are also crucial for clarifying the occurrence, migration, and enrichment mechanisms of helium in strata, and for improving my country's helium reservoir theory.

[0004] Related technologies use volumetric, gravimetric, and breakthrough curve methods to simulate helium adsorption behavior. However, these three traditional isothermal adsorption experimental methods all assume "zero helium adsorption" to calculate key experimental parameters. Due to their inherent principles, they are unable to measure the adsorption characteristics of helium.

[0005] Therefore, how to more deeply, accurately and effectively measure the adsorption capacity of helium has become an urgent problem to be solved. Summary of the Invention

[0006] In view of this, an embodiment of the present invention provides a helium isothermal adsorption measurement method based on a magnetic suspension balance, which at least solves the problem that related technologies cannot accurately and effectively measure the adsorption capacity of helium.

[0007] According to a first aspect of an embodiment of the present invention, a method for measuring helium isothermal adsorption based on a magnetic suspension balance is provided, comprising: After evacuating a magnetic levitation balance sample chamber storing a target sample at a first preset temperature for a preset time, obtaining a first mass of the target sample when the magnetic levitation balance sample chamber is at a temperature of an indoor environment; Obtaining a second mass and a volume of the sample frame corresponding to the target sample; and setting a plurality of adsorption temperature points, each of which includes a different adsorption pressure point; Obtaining the readings of the magnetic suspension balance corresponding to different adsorption pressure points at each adsorption temperature point and the free-phase helium density in the sample chamber of the magnetic suspension balance; Draw a linear relationship graph corresponding to each adsorption temperature point using the readings and the free-phase helium density, and calculate the slope of the linear relationship graph respectively; Performing ternary nonlinear fitting based on the multiple adsorption temperature points, the slope, the first mass, the sample frame volume and the ideal gas constant to obtain the unit mass skeleton volume of the target sample; Calculating the helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point based on the unit mass skeleton volume of the target sample, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium; The helium adsorption isotherm curve corresponding to each adsorption temperature point is drawn according to the helium adsorption amount, and the helium adsorption isotherm curve is fitted using the Langmuir formula to obtain the Langmuir maximum adsorption amount and Langmuir pressure corresponding to each adsorption temperature point.

[0008] According to a second aspect of an embodiment of the present invention, there is provided an electronic device comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform an operation corresponding to the method described in the first aspect.

[0009] According to a third aspect of an embodiment of the present invention, a computer storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the method according to the first aspect is implemented.

[0010] According to the solution provided by an embodiment of the present invention, after the magnetic levitation balance sample chamber storing the target sample is evacuated at a first preset temperature for a preset time, the first mass of the target sample is obtained when the magnetic levitation balance sample chamber is at the temperature of the indoor environment; the second mass of the sample frame corresponding to the target sample and the volume of the sample frame are obtained; and multiple adsorption temperature points are set, each adsorption temperature point includes a different adsorption pressure point; the readings of the magnetic levitation balance corresponding to the different adsorption pressure points at each adsorption temperature point and the free-phase helium density in the magnetic levitation balance sample chamber are obtained; a linear relationship graph corresponding to each adsorption temperature point is drawn using the readings and the free-phase helium density, and the slope of the linear relationship graph is calculated respectively; three-dimensional linear relationship is performed based on the multiple adsorption temperature points, the slope, the first mass, the sample frame volume and the ideal gas constant. The method comprises the following steps: performing nonlinear fitting of the element to obtain the unit mass skeleton volume of the target sample; calculating the helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point based on the unit mass skeleton volume of the target sample, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density and the atomic mass of helium; drawing the helium adsorption isotherm curve corresponding to each adsorption temperature point according to the helium adsorption amount, and fitting the helium isotherm curve using the Langmuir formula to obtain the Langmuir maximum adsorption amount and Langmuir pressure corresponding to each adsorption temperature point. In this process, based on the physical principle that the thermodynamic characteristics of helium adsorption at different temperatures obey the Arrhenius equation, combined with the testing principle of the magnetic levitation balance and the linear characteristics of the helium adsorption isotherm, a helium adsorption fitting model at multiple temperatures (i.e., the helium adsorption fitting formula) was established. The magnetic levitation balance was used to measure and plot the balance reading isotherms of the target sample after helium adsorption at different temperatures. The helium adsorption fitting model was used to fit and determine key parameters such as the sample's unit mass skeleton volume. The helium adsorption amount of the target sample under different temperature and pressure conditions was further calculated to achieve a quantitative evaluation of the helium adsorption capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which: Figure 1 A schematic flow chart of a helium isothermal adsorption measurement method based on a magnetic suspension balance provided in an embodiment of the present invention; Figure 2 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0013] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0014] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present invention are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present invention described here can be implemented in an order other than that illustrated or described here.

[0015] Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art in the art to which the embodiments of the present invention pertain. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art and, unless specifically defined as herein, should not be interpreted in an idealized or overly formal sense.

[0016] Figure 1 A flow chart of a helium isothermal adsorption measurement method based on a magnetic levitation balance provided in an embodiment of the present invention is provided. A helium isothermal adsorption measurement method based on a magnetic levitation balance provided in an embodiment of the present invention can be executed by an electronic device, such as a computer, a server, etc.

[0017] like Figure 1 As shown, the helium isothermal adsorption measurement method based on the magnetic suspension balance includes: S101, after evacuating a magnetic levitation balance sample chamber storing a target sample at a first preset temperature for a preset time, obtaining a first mass of the target sample when the magnetic levitation balance sample chamber is at an indoor temperature.

[0018] In the embodiments of the present invention, the target sample generally refers to a material with potential adsorption properties. Such materials can include porous materials (such as activated carbon, zeolites, metal-organic frameworks (MOFs)), nanostructured materials, novel synthetic materials, or any other solid material potentially useful for gas storage, separation, or catalytic applications. A 2-5 g sample is loaded into the sample chamber of a magnetic levitation balance. The chamber is evacuated at 433.15 K (a first preset temperature) for 10 hours. After the chamber cools to room temperature, the first mass of the target sample under vacuum is recorded.

[0019] S102 : Obtain a second mass and a volume of a sample frame corresponding to a target sample, and set a plurality of adsorption temperature points, each of which includes a different adsorption pressure point.

[0020] In an embodiment of the present invention, the sample frame is a physical frame or housing for holding the target sample, and the second mass and volume of the sample frame are measured. A plurality of different adsorption temperature points are set, and each adsorption temperature point includes a plurality of different adsorption pressure points.

[0021] Exemplarily, multiple (not less than 6) adsorption temperature points are selected under the temperature condition of 273.15~423.15 K, and each adsorption temperature point includes multiple (not less than 15) different adsorption pressure points.

[0022] S103 , obtaining the readings of the magnetic suspension balance corresponding to different adsorption pressure points at each adsorption temperature point and the density of the free-phase helium in the sample chamber of the magnetic suspension balance.

[0023] In an embodiment of the present invention, the readings of the magnetic levitation balance corresponding to different adsorption pressure points at each adsorption temperature point and the free-phase helium density in the sample chamber of the magnetic levitation balance are obtained, and finally multiple sets of data sets are obtained. Each set of data in the multiple sets of data sets includes an adsorption temperature point, multiple different adsorption pressure points, and the readings of the magnetic levitation balance corresponding to each adsorption pressure point and the free-phase helium density in the sample chamber of the magnetic levitation balance.

[0024] S104. Draw a linear relationship graph corresponding to each adsorption temperature point using the readings and the free-phase helium density, and calculate the slope of the linear relationship graph respectively.

[0025] In an embodiment of the present invention, a linear relationship graph corresponding to each adsorption temperature point is drawn using multiple sets of readings and the free-phase helium density, and the slope of each linear relationship graph is calculated. Ultimately, each adsorption temperature point corresponds to a slope.

[0026] S105, performing ternary nonlinear fitting based on multiple adsorption temperature points, slope, first mass, sample frame volume and ideal gas constant to obtain the unit mass skeleton volume of the target sample; In the embodiments of the present invention, the skeletal volume per unit mass of a target sample (i.e., specific skeletal volume or skeletal volume per unit mass) refers to the true skeletal volume (excluding pores and voids) per unit mass of the target sample. The skeletal volume per unit mass of the target sample is obtained by performing a three-variable nonlinear fit based on multiple adsorption temperature points, slope, first mass, volume, and ideal gas constant.

[0027] In an embodiment of the present invention, based on the testing principle of a magnetic levitation balance, the balance reading during the test is equal to the total mass of the sample frame, target sample, and adsorbed gas minus the buoyancy of the sample frame and target sample. According to the Archimedean principle, the buoyancy of the sample frame and target sample is equal to the weight of the free-phase gas displaced by the two, as shown in the following formula (1).

[0028] (1); In the above formula (1), m 读 is the reading of the magnetic suspension balance, unit is g; m 框 is the second mass, unit is g; m 样 is the first mass, unit is g; m 吸 is the mass of helium adsorbed by the target sample, in g; V 框 is the volume of the sample frame, in cm 3 ;v 样 is the unit mass skeleton volume of the target sample, in cm 3 / g; is the density of free-phase helium, in g / cm 3 .

[0029] Under low pressure conditions, the helium adsorption isotherm is usually linear and obeys Henry's law, as shown in the following formula (2): (2); In the above formula, n 吸 is the helium adsorption capacity of the target sample per unit mass, in mol / g; H is the Henry coefficient, in mol / g·MPa; p is the different adsorption pressure points, in MPa.

[0030] Helium adsorption per unit mass (n 吸 ) and the mass of adsorbed helium in the experiment (m 吸 ) has the following relationship: (3); In the above formula, M He is the atomic mass of helium, which is 4 g / mol.

[0031] The mass of adsorbed helium in the experiment is the total mass of helium actually adsorbed by the target sample.

[0032] According to the ideal gas state equation, the different adsorption pressure points p in the experimental device can be expressed by formula (4): (4); In the above formula, n 游 is the amount of free helium, in mol; V 游 is the volume of free phase helium, in cm 3 ; R is the ideal gas constant, which is 8.314 J / (mol·K); T is multiple adsorption temperature points, unit K; m 游 is the mass of the free phase gas, in g, is the density of free-phase helium, in g / cm 3 .

[0033] Substituting formulas (3) and (4) into formula (2) and converting them, we can get the following formula (5): (5); Substituting formula (5) into formula (1) and converting it, we can get the following formula (6): (6); In the helium isothermal adsorption experiment at a specific temperature, the sample frame mass (m 框 ) and the first mass (m 样 ) are constants, and the free phase helium density ( ) is the variable that changes with the experimental pressure, The coefficient of The various terms in are also constants, so the reading of the magnetic levitation balance obtained in the experiment (m 读 ) should be consistent with the free phase helium density ( ) is a straight line relationship, and the linear slope k can be expressed by the following formula: (7); The relationship between the Henry coefficient (H) of helium adsorption and multiple adsorption temperature points (T) obeys the Arrhenius equation, that is: (8); In the above formula, H0 is the adsorption enthalpy change coefficient, unit is mol / g·MPa; H1 is the isosteric adsorption heat, unit is J / mol.

[0034] Substituting formula (8) into formula (7) and converting it, we can get: (9); Formula (9) is the helium adsorption fitting model at multiple temperatures (i.e., the helium adsorption fitting formula). In the helium isothermal adsorption experiment under different temperature conditions for the same target sample using magnetic levitation, T in Formula (9) is the independent variable, k is the dependent variable, R, m 样 、V 框 are known constants, H0, H1, v 样 As unknown constants, the three-variable nonlinear fitting method can be used to determine H0, H1, and v 样 value.

[0035] S106. Calculate the helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point based on the unit mass skeleton volume, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium of the target sample.

[0036] In the embodiments of the present invention, the helium adsorption amount refers to the amount of helium molecules adsorbed by the surface or internal pores of the material. The helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point is calculated based on the helium adsorption amount formula, the unit mass skeleton volume, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium. Finally, each adsorption temperature point corresponds to multiple helium adsorption amounts. The helium adsorption amount formula is shown below (10): (10); In the above formula (10), n 吸 is the helium adsorption amount per unit mass of the target sample, m 读 is the reading of the magnetic suspension balance, m 框 is the second mass, m 样 is the first mass, m 吸 is the mass of helium adsorbed by the target sample, V 框 is the sample frame volume, v 样 is the skeleton volume per unit mass, is the density of free helium.

[0037] S107. Draw a helium isothermal adsorption curve corresponding to each adsorption temperature point according to the helium adsorption amount, and fit the helium isothermal adsorption curve using the Langmuir formula to obtain the Langmuir maximum adsorption amount and Langmuir pressure corresponding to each adsorption temperature point.

[0038] In an embodiment of the present invention, a helium adsorption isotherm curve corresponding to each adsorption temperature point is drawn based on the helium adsorption amount. The helium adsorption isotherm curve includes each adsorption pressure point and the corresponding helium adsorption amount. The Langmuir formula is as follows: (11); In the above formula (11), n0 is the maximum Langmuir adsorption capacity, unit is mol / g; P L is the Langmuir pressure, unit is MPa.

[0039] It is understood that, in the embodiment of the present invention, after the sample chamber of the magnetic levitation balance storing the target sample is evacuated at a first preset temperature for a preset time, the first mass of the target sample is obtained when the sample chamber of the magnetic levitation balance is at the temperature of the indoor environment; The second mass and volume of the sample frame corresponding to the target sample are obtained, and multiple adsorption temperature points are set, each of which includes different adsorption pressure points; the readings of the magnetic levitation balance and the free-phase helium density in the sample chamber of the magnetic levitation balance corresponding to the different adsorption pressure points at each adsorption temperature point are obtained; a linear relationship graph corresponding to each adsorption temperature point is plotted using the readings and the free-phase helium density, and the slopes of the linear relationship graphs are calculated respectively; a ternary nonlinear fitting is performed based on the multiple adsorption temperature points, the slopes, the first mass, the sample frame volume, and the ideal gas constant to obtain the unit mass skeleton volume of the target sample; the helium adsorption amount corresponding to the different adsorption pressure points at each adsorption temperature point is calculated based on the unit mass skeleton volume, the first mass, the second mass, the sample frame volume, the readings, the free-phase helium density, and the atomic mass of helium of the target sample; the helium adsorption isotherm curve corresponding to each adsorption temperature point is plotted based on the helium adsorption amount, and the helium isotherm curve is fitted using the Langmuir formula to obtain the Langmuir maximum adsorption amount and Langmuir pressure corresponding to each adsorption temperature point. In this process, based on the physical principle that the thermodynamic characteristics of helium adsorption at different temperatures obey the Arrhenius equation, combined with the testing principle of the magnetic levitation balance and the linear characteristics of the helium adsorption isotherm, a helium adsorption fitting model at multiple temperatures was established; the magnetic levitation balance was used to measure and plot the balance reading isotherms of the target sample after helium adsorption at different temperatures, and the helium adsorption fitting model was used to fit and determine key parameters such as the sample unit mass skeleton volume, and the helium adsorption amount of the target sample under different temperature and pressure conditions was further calculated to achieve a quantitative evaluation of the helium adsorption capacity.

[0040] In some embodiments of the invention, S102 can be implemented through S1021, which is explained through the following steps.

[0041] S1021. Traverse the parameters of the sample frame in the hardware parameters of the magnetic suspension balance, and obtain the second mass and the volume of the sample frame based on the parameters.

[0042] In some embodiments of the present invention, the hardware parameters of the magnetic levitation balance include multiple parameters, the parameters of the sample frame are found out from the multiple parameters, and then the second mass and volume of the sample frame are obtained.

[0043] Reference Figure 2, shows a schematic structural diagram of an electronic device according to an embodiment of the present invention. The specific embodiment of the present invention does not limit the specific implementation of the electronic device.

[0044] like Figure 2 As shown, the electronic device may include: a processor (processor) 502, a communication interface (Communications Interface 504), a memory (memory) 506, and a communication bus 508.

[0045] in: The processor 502 , the communication interface 504 , and the memory 506 communicate with each other via a communication bus 508 .

[0046] The communication interface 504 is used to communicate with other electronic devices or servers.

[0047] The processor 502 is configured to execute the program 510 , and specifically may execute the relevant steps in the above method embodiment.

[0048] Specifically, the program 510 may include program codes, which include computer operation instructions.

[0049] Processor 502 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The one or more processors included in a smart device may be of the same type, such as one or more CPUs, or different types, such as one or more CPUs and one or more ASICs.

[0050] The memory 506 is used to store the program 510. The memory 506 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk storage.

[0051] The program 510 may be specifically configured to enable the processor 502 to execute operations corresponding to the methods described in the above method embodiments.

[0052] The specific implementation of each step in program 510 can be found in the corresponding descriptions of the corresponding steps and units in the above-mentioned method embodiments, and will not be repeated here. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the above-mentioned devices and modules can refer to the corresponding process descriptions in the above-mentioned method embodiments, and will not be repeated here.

[0053] It should be pointed out that, according to the needs of implementation, the various components / steps described in the embodiments of the present invention can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present invention.

[0054] The methods according to the embodiments of the present invention described above can be implemented in hardware, firmware, or as software or computer code that can be stored on a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code originally stored on a remote recording medium or non-transitory machine-readable medium downloaded over a network and then stored on a local recording medium. Thus, the methods described herein can be processed by such software stored on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It will be understood that a computer, processor, microprocessor controller, or programmable hardware includes a storage component (e.g., RAM, ROM, flash memory, etc.) that can store or receive software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the methods described herein are implemented. Furthermore, when a general-purpose computer accesses the code for implementing the methods described herein, the execution of the code transforms the general-purpose computer into a dedicated computer for performing the methods described herein.

[0055] Those skilled in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present invention.

[0056] The above implementation methods are only used to illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present invention, and the scope of patent protection of the embodiments of the present invention should be defined by the claims.

Claims

1. A helium isothermal adsorption measurement method based on a magnetic suspension balance, characterized in that: include: After evacuating a magnetic levitation balance sample chamber storing a target sample at a first preset temperature for a preset time, obtaining a first mass of the target sample when the magnetic levitation balance sample chamber is at a temperature of an indoor environment; Obtaining a second mass and a volume of the sample frame corresponding to the target sample, and setting a plurality of adsorption temperature points, each of which includes a different adsorption pressure point; Obtaining the readings of the magnetic suspension balance corresponding to different adsorption pressure points at each adsorption temperature point and the free-phase helium density in the sample chamber of the magnetic suspension balance; Draw a linear relationship graph corresponding to each adsorption temperature point using the readings and the free-phase helium density, and calculate the slope of the linear relationship graph respectively; Performing ternary nonlinear fitting based on the multiple adsorption temperature points, the slope, the first mass, the sample frame volume and the ideal gas constant to obtain the unit mass skeleton volume of the target sample; Calculating the helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point based on the unit mass skeleton volume of the target sample, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium; The helium adsorption isotherm curve corresponding to each adsorption temperature point is drawn according to the helium adsorption amount, and the helium adsorption isotherm curve is fitted using the Langmuir formula to obtain the Langmuir maximum adsorption amount and Langmuir pressure corresponding to each adsorption temperature point.

2. The method according to claim 1, characterized in that The obtaining of the second mass and volume of the sample frame corresponding to the target sample includes: The parameters of the sample frame are traversed from the hardware parameters of the magnetic suspension balance, and the second mass and the volume of the sample frame are acquired based on the parameters.

3. The method according to claim 1, characterized in that The calculating of the helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point based on the unit mass skeleton volume of the target sample, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium includes: The helium adsorption amount corresponding to each adsorption pressure point at each adsorption temperature point is calculated according to the helium adsorption amount formula, the skeleton volume per unit mass, the first mass, the second mass, the sample frame volume, the reading, the free phase helium density, and the atomic mass of helium, wherein the helium adsorption amount formula is as follows: （10） In the above formula, n 吸 is the helium adsorption amount per unit mass of the target sample, m 读 is the reading of the magnetic suspension balance, m 框 is the second mass, m 样 is the first mass, m 吸 is the mass of helium adsorbed by the target sample, V 框 is the sample frame volume, v 样 is the unit mass skeleton volume, is the density of free helium.

4. The method according to claim 1, wherein The performing of ternary nonlinear fitting based on the multiple adsorption temperature points, the slope, the first mass, the sample frame volume, and the ideal gas constant to obtain the unit mass skeleton volume of the target sample includes: A ternary nonlinear fitting is performed based on a helium adsorption fitting formula, the multiple adsorption temperature points, the slope, the first mass, the volume, and the ideal gas constant to obtain the unit mass skeletal volume of the target sample, wherein the helium adsorption fitting formula is as follows: （9） In the above formula, k is the slope, H0 is the adsorption enthalpy change coefficient, H1 is the isosteric adsorption heat, T is the multiple adsorption temperature points, and R is the ideal gas constant.

5. The method according to claim 1, characterized in that The Langmuir formula is as follows: （11） In the above formula, P is the different adsorption pressure points, n0 is the maximum Langmuir adsorption capacity, P L For Langmuir pressure.

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