Method, system and equipment for determining storage state of supercritical hydrogen

Abstract

The invention relates to the technical field of hydrogen storage containers, and discloses a method, system and equipment for determining the storage state of supercritical hydrogen, and the method comprises the following steps: collecting the current temperature and the current pressure in a gas storage cylinder; calculating the current density of the supercritical hydrogen in the gas storage cylinder according to the current temperature and the current pressure; according to a comparison result between the current density and the maximum storage density, the current fullness rate of the storage gas cylinder is obtained; and comparing the current fullness rate with a safety threshold range of the storage gas cylinder to determine the storage state of the supercritical hydrogen in the storage gas cylinder. The supercritical hydrogen storage gas cylinder has the beneficial effect that the technical effect of improving the safety and the practicability of the supercritical hydrogen storage gas cylinder is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen storage containers, and in particular to a method, system and device for determining a supercritical hydrogen storage state. Background Art

[0002] Among the related technologies, low-temperature and high-pressure hydrogen storage technology has a higher hydrogen storage energy density than high-pressure gaseous hydrogen storage technology, and a longer medium lossless storage time than low-temperature liquid hydrogen storage technology. It is one of the most promising technologies in current physical hydrogen storage technology, and is also one of the important carrier forms for future hydrogen energy storage and utilization.

[0003] Storage cylinders are storage devices for low-temperature and high-pressure hydrogen. When hydrogen is stored under low-temperature and high-pressure conditions exceeding the critical temperature and critical pressure, the physical form of hydrogen is a single-phase supercritical hydrogen state. In terms of storage performance and safety level, supercritical hydrogen storage has been proven to be very promising.

[0004] However, in storage containers of fuel oil or liquid hydrogen, which are traditional energy sources, a liquid level gauge can be used to intuitively determine the storage status, but the same method cannot be applied to storage cylinders storing supercritical hydrogen. Therefore, it is urgent to provide a method to determine the storage status of supercritical hydrogen stored in storage cylinders. Summary of the invention

[0005] The present application provides a method, system and device for determining the supercritical hydrogen storage state, which solves the technical problem in the related art that it is difficult to directly determine the supercritical hydrogen storage state, and achieves the technical effect of improving the safety of supercritical hydrogen storage cylinders and the practicality of supercritical hydrogen storage cylinders.

[0006] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0007] In a first aspect, an embodiment of the present application provides a method for determining a supercritical hydrogen storage state.

[0008] The method for determining the storage state of supercritical hydrogen proposed in the embodiment of the present application, wherein the storage cylinder for storing the supercritical hydrogen is a low-temperature high-pressure container; the method comprises:

[0009] Collecting the current temperature and current pressure in the storage gas cylinder;

[0010] Calculating the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder;

[0011] According to the comparison result between the current density and the maximum storage density, the current filling rate of the storage cylinder is obtained; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder;

[0012] The current filling rate is compared with a safety threshold range of the storage cylinder to determine the storage state of supercritical hydrogen in the storage cylinder; wherein the safety threshold range is determined by the filling rate when the storage cylinder is in a normal state.

[0013] In the embodiment of the present application, due to the uniform nature of the temperature field and pressure field inside the storage cylinder storing supercritical hydrogen, the current temperature and current pressure inside the storage cylinder are collected, so as to convert the current temperature and current pressure inside the storage cylinder storing supercritical hydrogen into the corresponding current density, and compare the current density with the maximum storage density of the storage cylinder, and obtain the current filling rate of the supercritical hydrogen in the storage cylinder by comparing the result, so as to determine the storage state of the storage cylinder. By converting the temperature and pressure of the supercritical hydrogen in the storage cylinder into a filling rate that can accurately characterize the storage state of the storage cylinder, support is provided for low-temperature and high-pressure supercritical hydrogen storage technology, and the overall performance of the supercritical hydrogen storage system is also improved.

[0014] Optionally, before calculating the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure, the method further includes:

[0015] Determine the intermolecular force correction factor and hydrogen molecule volume correction factor based on the standard gas constant, the critical temperature and critical pressure of hydrogen;

[0016] The step of calculating the current density of supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure includes:

[0017] The current density is obtained by solving the state equation according to the current temperature, the current pressure, the standard gas constant, the intermolecular force correction coefficient, the hydrogen molecule volume correction coefficient and the hydrogen molecule molar mass.

[0018] Optionally, the current density is obtained by solving the following state equation:

[0019]

[0020] Wherein, P is the current pressure; T is the current temperature; ρ is the current density; R is the standard gas constant, which is 8.314 J / (mol·K); M m is the molar mass of hydrogen molecule, take 2.016×10 -3 kg / mol; a is the correction factor for intermolecular forces; b is the correction factor for the volume of hydrogen molecules.

[0021] Optionally, the intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient are determined in the following manner:

[0022] Obtaining the intermolecular force correction coefficient according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the first constant;

[0023] The hydrogen molecule volume correction coefficient is obtained according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the second constant.

[0024] Optionally, the intermolecular force correction coefficient is in the following form:

[0025]

[0026] The hydrogen molecule volume correction factor is in the following form:

[0027]

[0028] Among them, T c is the critical temperature of hydrogen; P c is the critical pressure of hydrogen; the first constant is set to 0.42748; the second constant is set to 0.08664.

[0029] Optionally, obtaining the current filling rate of the storage gas cylinder according to the comparison result between the current density and the maximum storage density includes:

[0030] Calculating a ratio of the current density to the maximum storage density as the current filling rate;

[0031] The maximum storage density is obtained based on the lowest design storage temperature and the highest design storage pressure of the storage cylinder.

[0032] Optionally, determining the storage state of the supercritical hydrogen in the storage cylinder according to the comparison result of the current filling rate and the safety threshold range of the storage cylinder includes at least one of the following:

[0033] When the current filling rate does not exceed a first threshold, determining that the storage gas cylinder is in an underfilled state, and triggering an underfill alarm;

[0034] When the current filling rate exceeds a first threshold value and does not exceed a second threshold value, determining that the storage gas cylinder is in a normal state;

[0035] When the current filling rate exceeds a second threshold, it is determined that the storage gas cylinder is in an overfilled state, and an overfill alarm is triggered.

[0036] Optionally, the lowest design storage temperature of the storage gas cylinder is not lower than the critical temperature of hydrogen, the highest design storage pressure of the storage gas cylinder is not lower than the critical pressure of hydrogen, and the current pressure does not exceed the highest design storage pressure.

[0037] In a second aspect, an embodiment of the present application provides a system for determining a supercritical hydrogen storage state.

[0038] The system for determining the storage state of supercritical hydrogen proposed in the embodiment of the present application is suitable for storing supercritical hydrogen in a storage cylinder that is a low-temperature and high-pressure container; the system comprises:

[0039] A data acquisition module, used to collect the current temperature and current pressure in the storage gas cylinder;

[0040] A density calculation module, used to calculate the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder;

[0041] A filling rate determination module, used to obtain the current filling rate of the storage cylinder according to the comparison result between the current density and the maximum storage density; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder;

[0042] A storage state determination module is used to compare the current filling rate with the safety threshold range of the storage gas cylinder to determine the storage state of supercritical hydrogen in the storage gas cylinder; wherein the safety threshold range is determined by the filling rate when the storage gas cylinder is in a normal state.

[0043] In a third aspect, an embodiment of the present application provides a computer device.

[0044] The computer device proposed in the embodiment of the present application includes:

[0045] A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for determining the supercritical hydrogen storage state described in any one of the above embodiments by executing the computer instructions.

[0046] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium.

[0047] The computer-readable storage medium proposed in the embodiments of the present application stores computer instructions, and the computer instructions are used to enable a computer to execute the method for determining the supercritical hydrogen storage state described in any one of the above embodiments.

[0048] In a fifth aspect, an embodiment of the present application provides a computer program product.

[0049] The computer program product proposed in the embodiments of the present application includes computer instructions, and the computer instructions are used to enable a computer to execute the method for determining the supercritical hydrogen storage state described in any of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A step diagram of a method for determining a supercritical hydrogen storage state provided in an embodiment of the present application;

[0052] Figure 2 This is a schematic diagram of the structure of the gas storage cylinder in the embodiment of the present application;

[0053] Figure 3 This is a schematic diagram of the variation of the density of supercritical hydrogen with temperature and pressure obtained by the table lookup method based on the NIST database;

[0054] Figure 4 This is a schematic diagram of the change of the filling rate of the storage gas cylinder with the change of temperature and pressure obtained by the table lookup comparison method based on the NIST database;

[0055] Figure 5 This is a schematic diagram of the variation of the density of supercritical hydrogen with temperature and pressure obtained based on the numerical solution method of the implicit function of the RK equation;

[0056] Figure 6 This is a schematic diagram of the variation of the filling rate of the storage gas cylinder with the temperature and pressure obtained based on the numerical solution method of the implicit function of the RK equation;

[0057] Figure 7 A module diagram of a system for determining a supercritical hydrogen storage state provided in an embodiment of the present application;

[0058] Figure 8 A schematic diagram of the structure of a computer device provided in an embodiment of the present application.

[0059] Among them, the figure numbers of the drawings in the specification are as follows: 100. Data acquisition module, 200. Density calculation module, 300. Filling rate determination module, 400. Storage status determination module, 501. Front end support of gas cylinder, 502. Inner liner of gas cylinder container, 503. Reinforcement layer of gas cylinder container, 504. Pressure sensor, 505. Temperature sensor, 506. High vacuum insulation interlayer, 507. Gas cylinder outer shell, 508. Rear end support of gas cylinder. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0061] As a novel clean energy, hydrogen has high calorific value and specific internal energy, and has the advantages of abundant reserves, wide sources, and multiple preparation methods. Currently, hydrogen energy has become an ideal choice to replace traditional fossil energy. Conventional storage methods for hydrogen include gaseous storage, liquid storage, and solid storage. Among them, researchers have proposed a new storage and transportation form based on liquid hydrogen research, namely supercritical hydrogen.

[0062] Low-temperature and high-pressure hydrogen storage technology that stores hydrogen in the form of supercritical hydrogen has a higher hydrogen storage energy density than high-pressure gaseous hydrogen storage technology, and a longer medium lossless storage time than low-temperature liquid hydrogen storage technology. It is one of the most promising technologies in current physical hydrogen storage technology and one of the important carrier forms for hydrogen energy storage in the future.

[0063] Storage cylinders are one of the storage devices for cryogenic and high-pressure supercritical hydrogen. When hydrogen is stored under low-temperature and high-pressure conditions exceeding the critical temperature and critical pressure, the physical form of hydrogen is a single-phase supercritical hydrogen state, which is more compressible than liquid hydrogen and has a greatly limited expansion capacity compared to hydrogen gas. It has a higher theoretical hydrogen storage density and a fast-charging process advantage. Currently, storage cylinders have been widely used as energy carriers in transportation vehicles, ships, aircraft, and other means of transportation.

[0064] The fuel stored in the fuel tank of a traditional fuel vehicle or the liquid hydrogen storage tank of a liquid hydrogen vehicle is in a liquid phase or a gas-liquid two-phase state, with a significant liquid level or gas-liquid interface. At this time, a float or electronic level gauge can be used to test the filling rate; however, low-temperature and high-pressure supercritical hydrogen is in a single-phase state, and the temperature and pressure of the internal supercritical hydrogen fluctuate in real time during the filling process, vehicle operation process, and vehicle shutdown process. It is difficult to evaluate the filling rate with a single parameter, and it is difficult to intuitively reflect the filling rate when using the dual parameters of temperature and pressure for evaluation. The above problems will cause the user to be unable to grasp the content of supercritical hydrogen in the storage cylinder during use, resulting in an inability to determine whether it needs to be filled. When too much supercritical hydrogen is filled in the storage cylinder, it will also bring certain safety issues.

[0065] The method, system and device for determining the storage state of supercritical hydrogen provided in this specification can be applied to determine the storage state of a storage cylinder storing supercritical hydrogen. The storage temperature inside the storage cylinder is not higher than 150K. When the temperature inside the storage cylinder is between the minimum design storage temperature and 150K, and the pressure is between the critical pressure of hydrogen and the maximum design storage pressure, the inside of the storage cylinder is all supercritical hydrogen in a single-phase state.

[0066] In addition, for storage containers storing other types of supercritical media, the present application can be adaptively modified, and the method, system and device for determining the supercritical hydrogen storage state provided in this specification can be applied to storage containers storing this type of supercritical medium, thereby determining the storage state of the corresponding type of supercritical medium.

[0067] According to an embodiment of the present application, an embodiment of a method for determining a supercritical hydrogen storage state is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0068] In this embodiment, a method for determining the storage state of supercritical hydrogen is provided, which can be used for the above-mentioned storage cylinder for storing supercritical hydrogen. Figure 1 The step diagram of the method for determining the supercritical hydrogen storage state provided in the embodiment of the present application, as shown in the figure, the method comprises the following steps:

[0069] S100. Collect the current temperature and current pressure in the storage gas cylinder.

[0070] S200. Calculate the current density of supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder.

[0071] S300. Obtain the current filling rate of the storage cylinder according to the comparison result between the current density and the maximum storage density; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder.

[0072] S400. Compare the current filling rate with the safety threshold range of the storage cylinder to determine the storage state of the supercritical hydrogen in the storage cylinder; wherein the safety threshold range is determined by the filling rate when the storage cylinder is in a normal state.

[0073] Specifically, a temperature sensor and a pressure sensor are provided in the storage cylinder, wherein the temperature sensor is used to monitor the current temperature of the supercritical hydrogen stored in the storage cylinder in real time and output it, and the pressure sensor is used to monitor the current pressure of the supercritical hydrogen stored in the storage cylinder in real time and output it, and both the temperature sensor and the pressure sensor are arranged at a position away from the inner wall of the storage cylinder.

[0074] The inventors have discovered that supercritical hydrogen molecules have strong mobility, and thus have the property of making the temperature field and pressure field inside the storage cylinder storing supercritical hydrogen uniform. However, within a certain distance from the inner wall of the storage cylinder, the mobility of supercritical hydrogen molecules decreases, resulting in the inability to display the above-mentioned properties, and thus the inability to monitor the current temperature and current pressure of the supercritical hydrogen stored in the storage cylinder in real time based on this property. Therefore, the temperature sensor and the pressure sensor need to be located away from the inner wall of the storage cylinder to improve the accuracy of the temperature and pressure measurement results, thereby improving the accuracy of the determined filling rate.

[0075] In some embodiments, the storage cylinder applicable to the above-mentioned method for determining the supercritical hydrogen storage state is a low-temperature high-pressure container, and its structure can refer to Figure 2 , Figure 2This is a schematic diagram of the structure of the gas cylinder in the embodiment of the present application. As shown in the figure, the main structure of the gas cylinder in the present embodiment includes a gas cylinder inner container and a gas cylinder outer shell 507. Among them, the gas cylinder inner container includes a gas cylinder inner container liner 502 and a gas cylinder inner container reinforcement layer 503. Supercritical hydrogen is stored in the gas cylinder inner container liner 502, and a pressure sensor 504 and a temperature sensor 505 are provided at a position away from the inner wall surface of the gas cylinder inner container liner 502, which are respectively used to monitor the current pressure and current temperature of the supercritical hydrogen stored in the storage cylinder. The gas cylinder inner container reinforcement layer 503 can be a reinforced fiber or a reinforced steel belt and steel wire structure, which is connected to the gas cylinder inner container liner 502 by winding, bonding or welding, and is used to improve the strength of the gas cylinder inner container. The gas cylinder inner container liner 502 is connected and fixed to the gas cylinder outer shell 507 through the gas cylinder front end support 501 and the gas cylinder rear end support 508, wherein the materials of the gas cylinder inner container liner 502 and the gas cylinder outer shell 507 are made of metal materials such as aluminum alloy or stainless steel. A high vacuum insulation interlayer 506 is formed between the gas cylinder inner container reinforcement layer 503 and the gas cylinder outer shell 507 to maintain the insulation storage of low-temperature and high-pressure supercritical hydrogen inside the gas cylinder.

[0076] In other embodiments, an automatic heating device is further provided inside the storage cylinder and is in direct contact with the stored supercritical hydrogen. The automatic heating device is connected to the temperature sensor 505 and receives the current temperature data output by the temperature sensor 505. If the current temperature drops to a temperature close to the critical temperature of hydrogen, the automatic heating device is automatically turned on to heat the supercritical hydrogen stored in the storage cylinder, thereby increasing the temperature of the supercritical hydrogen, so that the supercritical hydrogen is always in a single-phase state, thereby avoiding the precipitation of liquid phase components and causing a decrease in storage efficiency.

[0077] Furthermore, the density of the supercritical hydrogen in the storage cylinder changes with the change of the current temperature and the current pressure, and any combination of the current temperature and the current pressure can determine a fixed current density value of the supercritical hydrogen. When the supercritical hydrogen in the storage cylinder is used, it is numerically manifested as a decrease in the current pressure. At this time, regardless of whether the current temperature changes, the current pressure and the current temperature after use can determine a fixed current density after use, and the obtained current density after use is less than the current density before use. Through the above properties, the filling rate of the storage cylinder can be characterized by the change in the density of the supercritical hydrogen in the storage cylinder, thereby reflecting the storage state of the storage cylinder. It should be noted that the storage state mentioned in this embodiment is used to represent the current supercritical hydrogen content in the storage cylinder, and its form is a comparison of the current supercritical hydrogen content in the storage cylinder with the maximum supercritical hydrogen content that can be stored in the storage cylinder. Therefore, the user can understand whether the storage cylinder needs to be refilled and whether there is a safety risk through the storage state.

[0078] In some embodiments, the method for determining the current density of supercritical hydrogen includes a table lookup comparison method, which is to search and compare the density data of supercritical hydrogen recorded in an existing database based on the current temperature and current pressure obtained, thereby determining the current density of supercritical hydrogen stored in the storage cylinder. In this embodiment, the existing databases that can be used for query include but are not limited to: NIST database, IUPAC standard online library and chemical substance online database. In this embodiment, the data recorded in the NIST database are used for comparison, and the data recorded in the NIST database are shown in Table 1.

[0079] Table 1 Density table corresponding to temperature and pressure of supercritical hydrogen in NIST database

[0080]

[0081] Reference Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the variation of supercritical hydrogen density with temperature and pressure obtained by looking up a table based on the NIST database. Figure 4 This is a schematic diagram of the change of the filling rate of the storage gas cylinder with temperature and pressure obtained by the table lookup method based on the NIST database. As shown in the figure, the density of supercritical hydrogen is affected by temperature and pressure. With the increase of temperature and pressure, the density of supercritical hydrogen gradually increases, and the corresponding filling rate of the storage gas cylinder also gradually increases.

[0082] In other embodiments, there is a situation where the density data of supercritical hydrogen recorded in the existing database is only for some specific temperature values ​​and pressure values, and the temperature values ​​and pressure values ​​recorded in the existing data table do not correspond to the actual current temperature values ​​and current pressure values ​​in the storage cylinder, resulting in the inability to directly determine the density of supercritical hydrogen based on the records in the existing database. In this case, according to the numerical values ​​of the current temperature and the current pressure, the temperature values ​​and pressure values ​​adjacent to the current parameters can be selected from the data recorded in the existing database, and the bilinear interpolation method can be used to determine the specific density values ​​corresponding to the current temperature and the current pressure based on the density values ​​corresponding to the adjacent temperature values ​​and pressure values.

[0083] Specifically, when solving the density of supercritical hydrogen by the bilinear interpolation method according to the temperature and pressure that do not correspond to the data recorded in the existing database, there are cases where only the temperature does not correspond, only the pressure does not correspond, and both the temperature and the pressure do not correspond. When only the temperature does not correspond, a temperature value adjacent to the current temperature is selected, and the specific density value corresponding to the current temperature and the current pressure is determined according to the following formula:

[0084]

[0085] Among them, ρ 1 is the current density at this time; T is the current temperature; T 1 and T 2 are the temperatures adjacent to the current temperature; ρ a and ρ b are respectively the temperature T at the current pressure 1 and T 2 The corresponding density.

[0086] It is understandable that when only the pressure does not correspond, a pressure value adjacent to the current pressure is selected, and the specific density value corresponding to the current temperature and the current pressure is determined according to the following formula:

[0087]

[0088] Among them, ρ 2 is the current density at this time; P is the current pressure; P 1 and P 2 are the pressures adjacent to the current temperature; ρ c and ρ d are the pressure P at the current temperature 1 and P 2 The corresponding density.

[0089] When the temperature and pressure do not correspond, select the temperature value adjacent to the current temperature and the pressure value adjacent to the current pressure respectively. First, according to the adjacent temperature data, linear interpolation of the pressure is performed according to the following formula:

[0090]

[0091] Among them, ρ 1 is the current pressure and the adjacent temperature T 1 The corresponding density; ρ 2 is the current pressure and the adjacent temperature T 2 The corresponding density; P is the current pressure; P 1 and P 2 are the pressures adjacent to the current temperature; ρ e is the temperature T 1 and pressure P 2 The corresponding density; ρ f is the temperature T 1 and pressure P 1 The corresponding density; ρ g is the temperature T 2 and pressure P 2 The corresponding density; ρ h is the temperature T 2 and pressure P 1Corresponding density. According to the corresponding adjacent temperature data and the density of the current pressure, the temperature is further linearly interpolated based on the following formula:

[0092]

[0093] Among them, ρ 3 is the current density; T is the current temperature. It is understandable that in this case, the temperature can be linearly interpolated first, and then the pressure can be linearly interpolated. According to the above equation, the current density of supercritical hydrogen corresponding to the current temperature and the current pressure can be obtained in different cases.

[0094] Furthermore, supercritical hydrogen has a maximum storage density when stored in a storage cylinder, and the maximum storage density is used to limit the total amount of supercritical hydrogen that can be stored in the storage cylinder. The method for determining the maximum storage density includes calculation and manual setting based on the design parameters of the storage cylinder, wherein the maximum storage density can be limited according to the actual application scenario during manual setting, and the basis for setting may include but is not limited to: if the use environment or transportation environment of the storage cylinder has high requirements for safety, a smaller maximum storage density can be designed to limit the total amount of supercritical hydrogen in the storage cylinder to avoid safety problems during use and transportation; if the use environment of the storage cylinder has high requirements for continuous energy output, a larger maximum storage density can be designed to meet long-term energy output. It should be noted that the maximum storage density at this time should be less than the storage density determined according to the design parameters of the storage cylinder.

[0095] In the method for determining the supercritical hydrogen storage state provided in this embodiment, the filling rate of the storage cylinder is determined by comparing the current density with the maximum storage density. The comparison result can be obtained in a variety of ways, including but not limited to: finding the difference between the current density and the maximum storage density, and determining the filling rate of the storage cylinder according to the obtained difference. At this time, the filling rate is inversely proportional to the obtained difference. The larger the obtained difference, the lower the filling rate of the storage cylinder; the smaller the obtained difference, the higher the filling rate of the storage cylinder.

[0096] Furthermore, the obtained filling rate is compared with the safety threshold range corresponding to the storage cylinder to determine the storage state of supercritical hydrogen in the storage cylinder. Among them, the safety threshold range is determined by the filling rate when the storage cylinder is in a normal state. The normal working state can be set according to the actual situation. The basis for setting may include but is not limited to: if the use environment or transportation environment of the storage cylinder has high requirements for safety, the upper limit of the safety threshold range can be set to a lower value, thereby reducing the filling rate of supercritical hydrogen in the storage cylinder under normal working conditions and improving safety during use and transportation; if the use environment of the storage cylinder has high requirements for continuous energy output, the lower limit of the safety threshold range can be set to a higher value, so that when the filling rate is low, the user can be reminded to fill it in time to meet the user's needs for long-term energy output. It can be understood that the lower limit of the safety threshold range should not be lower than 0.

[0097] In the above-mentioned method for determining the storage state of supercritical hydrogen, due to the uniform nature of the temperature field and pressure field inside the storage cylinder of supercritical hydrogen, the current temperature and current pressure inside the storage cylinder are collected, so as to convert the current temperature and current pressure inside the storage cylinder storing supercritical hydrogen into the corresponding current density, and compare the current density with the maximum storage density of the storage cylinder, and obtain the current filling rate of the supercritical hydrogen in the storage cylinder by comparing the result, so as to determine the storage state of the storage cylinder. By converting the temperature and pressure of the supercritical hydrogen in the storage cylinder into a filling rate that can accurately characterize the storage state of the storage cylinder, support is provided for the low-temperature and high-pressure supercritical hydrogen storage technology, and the overall performance of the supercritical hydrogen storage system is also improved.

[0098] As an embodiment of the present application, before calculating the current density of supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure, the method further includes:

[0099] S210. Determine the intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient based on the standard gas constant, the critical temperature and critical pressure of hydrogen.

[0100] According to the current temperature and the current pressure, the current density of supercritical hydrogen in the storage cylinder is calculated, including:

[0101] S220. Solve the state equation according to the current temperature, current pressure, standard gas constant, intermolecular force correction coefficient, hydrogen molecule volume correction coefficient and hydrogen molecule molar mass to obtain the current density.

[0102] Specifically, the method for determining the density of supercritical hydrogen in the storage cylinder in this embodiment is to solve the state equation according to the current temperature and the current pressure.

[0103] Furthermore, the state equation used includes an intermolecular force correction coefficient and a hydrogen molecule volume correction coefficient, wherein the intermolecular force correction coefficient is related to the intermolecular attraction, and therefore its value is related to the type of molecule. The method provided in this embodiment is designed for the storage state of supercritical hydrogen, and therefore the intermolecular force correction coefficient is determined by the parameters corresponding to hydrogen and the constants commonly used in the art; in other embodiments, when the medium stored in the storage cylinder is other types of supercritical media, the corresponding intermolecular force correction coefficient can be determined by the parameters corresponding to the type of supercritical medium.

[0104] The molecular volume correction factor is related to the volume of the molecule itself. It can be understood that the method provided in this embodiment is designed for the storage state of supercritical hydrogen. Therefore, the hydrogen molecular volume correction factor is determined by the parameters corresponding to hydrogen and the common constants in the field, that is, the hydrogen molecular volume correction factor; in other embodiments, when the medium stored in the storage cylinder is other types of supercritical media, the corresponding molecular volume correction factor can be determined by the parameters corresponding to this type of supercritical medium.

[0105] Further, according to the obtained intermolecular force correction coefficient and hydrogen molecule volume correction coefficient, combined with the measured current temperature and current pressure, an implicit function numerical equation about the current density can be obtained based on the state equation, and the current density of supercritical hydrogen in the storage cylinder can be obtained by solving the implicit function numerical equation. In some embodiments, the types of state equations include but are not limited to: van der Waals equation, Redlich-Kwong equation, Berthelot equation, Dieterici equation, etc.

[0106] In the above-mentioned method for determining the storage state of supercritical hydrogen, the corresponding current density is determined by solving the state equation according to the current temperature and current pressure of the supercritical hydrogen stored in the storage cylinder. Since the present embodiment uses an implicit function to solve a numerical solution, it has the advantage of high calculation accuracy, and the current density determined is highly accurate, which can accurately reflect the storage state of supercritical hydrogen inside the storage cylinder. It is understandable that the computational cost of the implicit function to solve the numerical solution is relatively high. When the required computational cost cannot be met in the actual application scenario, the current density can be determined by a table lookup method.

[0107] As an embodiment of the present application, the current density is obtained by solving the following state equation:

[0108]

[0109] Where P is the current pressure; T is the current temperature; ρ is the current density; R is the standard gas constant, which is 8.314 J / (mol·K); Mm is the molar mass of hydrogen molecule, take 2.016×10 -3 kg / mol; a is the correction factor for intermolecular forces; b is the correction factor for the volume of hydrogen molecules.

[0110] Specifically, the state equation used in this embodiment is the Redlich-Kwong equation (hereinafter referred to as the RK equation). The RK equation is a state equation based on the van der Waals equation in physical chemistry that approximately describes the behavior of real gases. Compared with the van der Waals equation and most multivariate real gas equations, the RK equation is more accurate in predicting the real gas behavior of hydrogen. Therefore, in this embodiment, the RK equation is used to solve the current density of supercritical hydrogen stored in the storage cylinder. In this embodiment, after substituting various data, the RK equation can be converted into a quadratic equation related to the current density, and the current density of supercritical hydrogen stored in the storage cylinder can be obtained by solving the equation.

[0111] It should be noted that the RK equation does not perform well when a liquid phase is involved, and therefore cannot be used to accurately calculate the gas-liquid equilibrium. In this embodiment, the supercritical hydrogen stored in the storage cylinder is in a single-phase state, thereby avoiding affecting the accuracy of the RK equation.

[0112] As an embodiment of the present application, the intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient are determined in the following manner:

[0113] S212. Obtain the intermolecular force correction coefficient based on the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the first constant.

[0114] S214. Obtain the hydrogen molecular volume correction coefficient based on the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the second constant.

[0115] Specifically, the intermolecular force correction coefficient can be determined according to the parameters corresponding to hydrogen and the commonly used constants in the art, which is used to correct the intermolecular attraction. The parameters corresponding to hydrogen include the critical temperature and the critical pressure of hydrogen, and the commonly used constants in the art include the standard gas constant and the first constant.

[0116] Specifically, the hydrogen molecular volume correction coefficient can be determined according to the parameters corresponding to hydrogen and the commonly used constants in the art, and is used to correct the molecular volume. The parameters corresponding to hydrogen include the critical temperature and the critical pressure of hydrogen, and the commonly used constants in the art include the standard gas constant and the second constant.

[0117] As an embodiment of the present application, the intermolecular force correction coefficient a is in the following form:

[0118]

[0119] The hydrogen molecule volume correction factor b is as follows:

[0120]

[0121] Among them, T c is the critical temperature of hydrogen; P c is the critical pressure of hydrogen; the first constant is set to 0.42748; the second constant is set to 0.08664.

[0122] In some embodiments, by substituting the critical temperature and critical pressure of other supercritical media, the above-mentioned method for determining the supercritical hydrogen storage state can be applied to calculate the current density of other supercritical media stored in the storage cylinder. In other embodiments, the intermolecular force correction factor and the hydrogen molecule volume correction factor can also be obtained by regression of experimental data.

[0123] Reference Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the variation of the density of supercritical hydrogen with temperature and pressure obtained based on the numerical solution method of the RK equation implicit function. Figure 6 This is a schematic diagram of the change of the filling rate of the storage gas cylinder with temperature and pressure obtained based on the numerical solution method of the implicit function of the RK equation. As shown in the figure, the density of supercritical hydrogen is affected by temperature and pressure. With the increase of temperature and pressure, the density of supercritical hydrogen gradually increases, and the corresponding filling rate of the storage gas cylinder also gradually increases.

[0124] Will Figure 5 and Figure 6 and Figure 3 and Figure 4 By comparison, it can be seen that the density results and filling rate results obtained by the two methods are similar. Therefore, one of the two methods can be selected arbitrarily during the calculation process without affecting the accuracy of the results.

[0125] As an embodiment of the present application, according to the comparison result between the current density and the maximum storage density, the current filling rate of the storage gas cylinder is obtained, including:

[0126] S310. Calculate the ratio of the current density to the maximum storage density as the current filling rate.

[0127] The maximum storage density is obtained based on the lowest design storage temperature and the highest design storage pressure of the storage cylinder.

[0128] Specifically, the current filling rate determined in this embodiment is the ratio of the current density to the maximum storage density, expressed as a percentage, in the following form:

[0129] δ=ρ

[0130] ρ d

[0131] Among them, δ is the current filling rate; ρ is the current density; ρ d is the maximum storage density. It can be understood that the current filling rate is a non-negative number.

[0132] Furthermore, the maximum storage density is obtained according to the lowest design storage temperature and the highest design storage pressure of the storage cylinder. According to the combination of the lowest design storage temperature and the highest design storage pressure of the storage cylinder, a unique storage density can be determined, which represents the maximum density of supercritical hydrogen that can be stored in the storage cylinder. It is understandable that when the current density of the supercritical hydrogen stored in the storage cylinder is greater than the maximum storage density, there is a safety risk in the storage cylinder.

[0133] As an embodiment of the present application, determining the storage state of supercritical hydrogen in the storage cylinder according to the comparison result between the current filling rate and the safety threshold range of the storage cylinder includes at least one of the following:

[0134] S410. When the current filling rate does not exceed the first threshold, it is determined that the storage gas cylinder is in an underfilled state, and an underfill alarm is triggered.

[0135] S420. When the current filling rate exceeds the first threshold and does not exceed the second threshold, it is determined that the storage gas cylinder is in a normal state.

[0136] S430. When the current filling rate exceeds the second threshold, it is determined that the storage gas cylinder is in an overfilled state and an overfill alarm is triggered.

[0137] Specifically, the safety threshold range is that the current filling rate exceeds the first threshold and does not exceed the second threshold. It can be understood that the second threshold is greater than the first threshold. When the current filling rate of the supercritical hydrogen stored in the storage cylinder is within the safety threshold range, the storage cylinder can work normally, that is, there is no safety risk, and it can also support the user's continuous use for a certain period of time.

[0138] Furthermore, the first threshold is a non-negative number. If the current filling rate does not exceed the first threshold, it means that the total amount of supercritical hydrogen stored in the storage cylinder is small and cannot meet the energy needs of the user. At this time, the storage cylinder is determined to be underfilled, and an underfill alarm is triggered to prompt the user to fill the storage cylinder as soon as possible. In this embodiment, the first threshold can be 10%.

[0139] Furthermore, the second threshold is a non-negative number. If the current filling rate exceeds the second threshold, it means that the total amount of supercritical hydrogen stored in the storage cylinder is too much, which has exceeded the maximum storage density of the storage cylinder or there is a risk of exceeding the maximum storage density of the storage cylinder. At this time, the storage cylinder is determined to be overfilled, and an overfill alarm is triggered to prompt the user to release the storage cylinder as soon as possible to avoid safety accidents. In this embodiment, the second threshold can be 100%.

[0140] As an embodiment of the present application, the minimum design storage temperature of the storage cylinder is not lower than the critical temperature of hydrogen, the maximum design storage pressure of the storage cylinder is not lower than the critical pressure of hydrogen, and the current pressure does not exceed the maximum design storage pressure.

[0141] Specifically, the critical temperature of hydrogen is 33.1K, so the minimum design storage temperature of the storage cylinder is not less than 33.1K. The critical pressure of hydrogen is 1.3MPa, so the maximum design storage pressure of the storage cylinder is not less than 1.3MPa. It can be obtained that the storage temperature range of the storage cylinder is from the lowest design storage temperature to 150K, and the storage pressure range is from 1.3MPa to the maximum design storage pressure. When the storage temperature in the storage cylinder is not less than the critical temperature of hydrogen and not less than the critical pressure of hydrogen, the supercritical hydrogen stored in the storage cylinder can be in a single-phase state, reducing the probability of supercritical hydrogen liquefaction and improving the storage efficiency of the storage cylinder.

[0142] In some embodiments, the preferred storage temperature range in the storage cylinder is 34K-150K, and the preferred storage pressure range is 10MPa-70Mpa.

[0143] Based on the above-mentioned method for determining the supercritical hydrogen storage state, the application of the method in multiple practical scenarios is provided below. In the following practical scenarios, the safety threshold range of the storage cylinder is 10%-100%.

[0144] In the first actual scenario, the storage cylinder is suitable for hydrogen fuel passenger cars. The hydrogen fuel passenger cars are equipped with storage cylinders with a volume of 140L, a nominal working pressure of 35MPa, and a minimum design storage temperature of 50K for the storage of supercritical hydrogen. The inner liner of the cylinder adopts T700 carbon fiber wrapped stainless steel liner as the inner container, and the outer shell structure adopts a stainless steel shell structure.

[0145] The storage gas cylinder is filled for the first time after leaving the factory, and supercritical hydrogen with a temperature of 34K is added to the cylinder. When the pressure in the storage gas cylinder rises to 35MPa, reaching the nominal working pressure of the cylinder, the filling port automatically jumps out of the gun to stop filling. At this time, the temperature and pressure sensors monitor that the pressure of the supercritical hydrogen in the bottle is 35MPa and the temperature is 50K.

[0146] At this time, the comparison is performed based on the NIST database through the table lookup method. The data recorded in the NIST database is shown in Table 1. According to Table 1, the maximum storage density under the conditions of the lowest design storage temperature and the highest design storage pressure is obtained, and the corresponding supercritical hydrogen density is obtained by looking up the table according to the current temperature and current pressure data monitored after the filling is completed, which just corresponds to the existing data in the table, which is 77.11kg / m 3 The current filling rate is calculated according to the current filling rate calculation formula to be 100%, indicating that the supercritical hydrogen in the storage cylinder is fully filled and within the safety threshold range, that is, the supercritical hydrogen reserves in the storage cylinder are sufficient for hydrogen fuel passenger cars to drive long distances.

[0147] In the second actual scenario, the storage cylinder is suitable for hydrogen fuel passenger cars. The hydrogen fuel passenger cars are equipped with storage cylinders with a volume of 155L, a nominal working pressure of 70MPa, and a minimum design storage temperature of 50K for the storage of supercritical hydrogen. The inner liner of the cylinder adopts T700 carbon fiber wrapped aluminum alloy liner as the inner container, and the outer shell structure adopts a stainless steel shell structure.

[0148] After the hydrogen fuel passenger car is running, the temperature sensor and pressure sensor in the storage cylinder monitor that the current pressure of supercritical hydrogen in the storage cylinder is 12.2MPa and the current temperature is 125.6K. At this time, based on the RK equation implicit function numerical solution method, the current temperature and current pressure are substituted into the intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient, and it can be determined that the intermolecular force correction coefficient is 0.144 and the hydrogen molecule volume correction coefficient is 1.842×10 -5 Substituting the above data into the RK equation and solving it numerically through implicit function, we can get the current density of supercritical hydrogen to be 20.89 kg / m 3 .

[0149] In addition, based on the implicit function numerical solution method of the RK equation, the maximum storage density of the storage cylinder under the conditions of the lowest design storage temperature and the highest design storage pressure is 87.81 kg / m 3 According to the obtained current density and maximum storage density, based on the calculation formula of the current filling rate, it can be obtained that the current filling rate of the supercritical hydrogen stored in the storage cylinder is 23.69%. At this time, the current filling rate of the supercritical hydrogen stored in the storage cylinder is within the safety threshold range, and the storage cylinder is determined to be in a normal state, which can be used for hydrogen fuel passenger cars to travel a certain mileage.

[0150] In the third actual scenario, the storage cylinder is suitable for hydrogen fuel commercial vehicles. The hydrogen fuel commercial vehicle is equipped with a storage cylinder with a volume of 1000L, a nominal working pressure of 20MPa, and a minimum design storage temperature of 50K for the storage of supercritical hydrogen. The inner liner of the storage cylinder uses a glass fiber wrapped stainless steel liner as the inner container, and the outer shell structure is stainless steel. After the transportation is completed, the hydrogen fuel commercial vehicle needs to go through a 5-day shutdown state. Before the shutdown, the temperature sensor and pressure sensor in the storage cylinder monitored that the pressure of the supercritical hydrogen in the storage cylinder was 11.8MPa and the temperature was 73.2K.

[0151] At this time, the table is used for comparison based on the NIST database. The data recorded in the NIST database is shown in Table 1. The measured current temperature and current pressure data are looked up in the table to obtain the corresponding supercritical hydrogen density. However, the current temperature and current pressure do not have direct corresponding values ​​in the table, so the bilinear interpolation method is required to obtain the current density. Based on Table 1, the two temperature values ​​adjacent to the current temperature T (73.2K) in the table are T 1 (70K) and T 2 (90K), the two pressure values ​​adjacent to the current pressure P (11.8MPa) in the table are P 1 (10MPa) and P 2 (15MPa), the supercritical hydrogen density under the combination of adjacent temperature and adjacent pressure is obtained according to Table 1, including:

[0152] (P 1 ,T 1 ,ρ a )→(10MPa,70K,35.30kg / m 3 )

[0153] (P 1 ,T 2 ,ρ b )→(10MPa,90K,25.94kg / m 3 )

[0154] (P 2 ,T 1 ,ρ c )→(15MPa,70K,46.31kg / m 3 )

[0155] (P 2 ,T 2 ,ρ d )→(15MPa,90K,35.83kg / m 3 )

[0156] First, interpolate the adjacent pressures to obtain the intermediate density variable ρ 1 and ρ2 , where ρ 1 39.26kg / m 3 , ρ 2 29.50kg / m 3 Secondly, according to the intermediate density variable ρ 1 and ρ 2 By interpolating adjacent temperatures, it can be obtained that at the current temperature of 73.2K and the current pressure of 11.8MPa, the current density of supercritical hydrogen is 37.98kg / m 3 .

[0157] In addition, the comparison was performed based on the NIST database by looking up the table. The data recorded in the NIST database is shown in Table 1. According to the minimum design storage temperature of 50K and the maximum design storage pressure of 20MPa, the maximum storage density of the storage cylinder is 66.82kg / m 3 .

[0158] Substituting the current density and the maximum storage density into the current filling rate formula, the current filling rate is calculated to be 56.84%. At this time, the current filling rate of the supercritical hydrogen stored in the storage cylinder is within the safety threshold range, and the storage cylinder is determined to be in a normal state, which can be used for hydrogen fuel commercial vehicles to travel a certain mileage.

[0159] The present application also provides a system for determining the supercritical hydrogen storage state, which can be applied to the above-mentioned method for determining the supercritical hydrogen storage state. Figure 7 , Figure 7 The module diagram of the system for determining the storage state of supercritical hydrogen provided in the embodiment of the present application is shown in the figure. As shown in the figure, the system includes a data acquisition module 100, a density calculation module 200, a filling rate determination module 300 and a storage state determination module 400, wherein:

[0160] The data acquisition module 100 is used to collect the current temperature and current pressure in the storage gas cylinder.

[0161] The density calculation module 200 is used to calculate the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder.

[0162] The filling rate determination module 300 is used to obtain the current filling rate of the storage cylinder based on the comparison result between the current density and the maximum storage density; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder.

[0163] The storage state determination module 400 is used to compare the current filling rate with the safety threshold range of the storage cylinder to determine the storage state of supercritical hydrogen in the storage cylinder; wherein the safety threshold range is determined by the filling rate when the storage cylinder is in a normal state.

[0164] In some optional implementations, the density calculation module 200 includes a coefficient calculation unit and an equation solving unit, wherein:

[0165] The coefficient calculation unit is used to determine the intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient according to the standard gas constant, the critical temperature and the critical pressure of hydrogen.

[0166] The equation solving unit is used to solve the state equation according to the current temperature, the current pressure, the standard gas constant, the intermolecular force correction factor, the hydrogen molecule volume correction factor and the hydrogen molecule molar mass to obtain the current density.

[0167] In some other embodiments, the equation solving unit obtains the current density by solving the following state equation:

[0168]

[0169] Where P is the current pressure; T is the current temperature; ρ is the current density; R is the standard gas constant, which is 8.314 J / (mol·K); M m is the molar mass of hydrogen molecule, take 2.016×10 -3 kg / mol; a is the correction factor for intermolecular forces; b is the correction factor for the volume of hydrogen molecules.

[0170] In some optional embodiments, the coefficient calculation unit includes an intermolecular force correction subunit and a hydrogen molecule volume correction subunit, wherein:

[0171] The intermolecular force correction subunit is used to obtain the intermolecular force correction coefficient according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the first constant.

[0172] The hydrogen molecule volume correction subunit is used to obtain the hydrogen molecule volume correction coefficient according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the second constant.

[0173] In other embodiments, the intermolecular force correction coefficient a in the intermolecular force correction subunit is in the following form:

[0174]

[0175] Among them, T c is the critical temperature of hydrogen; P c is the critical pressure of hydrogen; the first constant is set to 0.42748.

[0176] In other embodiments, the hydrogen molecule volume correction coefficient b in the hydrogen molecule volume correction subunit is in the following form:

[0177]

[0178] Among them, T c is the critical temperature of hydrogen; P c is the critical pressure of hydrogen; the second constant is 0.08664.

[0179] In some optional implementations, the fullness determination module 300 includes a fullness calculation unit and a maximum storage density calculation unit, wherein:

[0180] The filling rate calculation unit is used to calculate the ratio of the current density and the maximum storage density as the current filling rate.

[0181] The maximum storage density calculation unit is used to obtain the maximum storage density, which is obtained based on the minimum design storage temperature and maximum design storage pressure of the storage cylinder.

[0182] In some optional implementations, the storage state determination module 400 includes an undercharge state unit, a normal state unit, and an overcharge state unit, wherein:

[0183] The underfill status unit is used to determine that the storage gas cylinder is in an underfill state and trigger an underfill alarm when the current filling rate does not exceed a first threshold value.

[0184] The normal state unit is used to determine that the storage gas cylinder is in a normal state when the current filling rate exceeds a first threshold value and does not exceed a second threshold value.

[0185] The overcharge status unit is used to determine that the storage gas cylinder is in an overcharge state and trigger an overcharge alarm when the current filling rate exceeds a second threshold value.

[0186] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0187] The system for determining the supercritical hydrogen storage state in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0188] See also Figure 8 , Figure 8 is a schematic diagram of the structure of a computer device provided in an embodiment of the present application, such as Figure 8As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 10 is taken as an example.

[0189] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0190] The memory 20 stores instructions executable by at least one processor 10, so that at least one processor 10 executes the method shown in the above embodiment.

[0191] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0192] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0193] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0194] The embodiment of the present application also provides a computer-readable storage medium. The above method according to the embodiment of the present application can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0195] The embodiment of the present application provides a computer program product, which includes computer instructions, which are stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the method of any embodiment of the present application.

[0196] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

[0197] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0198] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0199] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0200] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0201] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0202] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0203] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0204] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0205] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

[0206] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for determining a supercritical hydrogen storage state, characterized in that: The storage cylinder for storing the supercritical hydrogen is a low-temperature high-pressure container; the method comprises: Collecting the current temperature and current pressure in the storage gas cylinder; Calculating the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder; According to the comparison result between the current density and the maximum storage density, the current filling rate of the storage cylinder is obtained; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder; The current filling rate is compared with a safety threshold range of the storage cylinder to determine the storage state of supercritical hydrogen in the storage cylinder; wherein the safety threshold range is determined by the filling rate when the storage cylinder is in a normal state.

2. The method according to claim 1, characterized in that: Before calculating the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure, the method further includes: Determine the intermolecular force correction factor and hydrogen molecule volume correction factor based on the standard gas constant, the critical temperature and critical pressure of hydrogen; The step of calculating the current density of supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure includes: The current density is obtained by solving the state equation according to the current temperature, the current pressure, the standard gas constant, the intermolecular force correction coefficient, the hydrogen molecule volume correction coefficient and the hydrogen molecule molar mass.

3. The method according to claim 2, characterized in that The current density is obtained by solving the following state equation: Wherein, P is the current pressure; T is the current temperature; ρ is the current density; R is the standard gas constant, which is 8.314 J / (mol·K); M m is the molar mass of hydrogen molecule, take 2.016×10 -3 kg / mol; a is the correction factor for intermolecular forces; b is the correction factor for the volume of hydrogen molecules.

4. The method according to claim 2, characterized in that: The intermolecular force correction coefficient and the hydrogen molecule volume correction coefficient are determined by the following method: Obtaining the intermolecular force correction coefficient according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the first constant; The hydrogen molecule volume correction coefficient is obtained according to the standard gas constant, the critical temperature of hydrogen, the critical pressure of hydrogen and the second constant.

5. The method according to claim 4, characterized in that The intermolecular force correction coefficient a is in the following form: The hydrogen molecule volume correction coefficient b is in the following form: Among them, T c is the critical temperature of hydrogen; P c is the critical pressure of hydrogen; the first constant is set to 0.42748; the second constant is set to 0.08664.

6. The method according to claim 1, characterized in that The step of obtaining the current filling rate of the storage gas cylinder according to the comparison result between the current density and the maximum storage density includes: Calculating a ratio of the current density to the maximum storage density as the current filling rate; The maximum storage density is obtained based on the lowest design storage temperature and the highest design storage pressure of the storage cylinder.

7. The method according to claim 1, characterized in that The step of determining the storage state of the supercritical hydrogen in the storage cylinder according to the comparison result between the current filling rate and the safety threshold range of the storage cylinder comprises at least one of the following: When the current filling rate does not exceed a first threshold, determining that the storage gas cylinder is in an underfilled state, and triggering an underfill alarm; When the current filling rate exceeds a first threshold value and does not exceed a second threshold value, determining that the storage gas cylinder is in a normal state; When the current filling rate exceeds a second threshold, it is determined that the storage gas cylinder is in an overfilled state, and an overfill alarm is triggered.

8. The method according to any one of claims 1 to 7, characterized in that The lowest design storage temperature of the storage gas cylinder is not lower than the critical temperature of hydrogen, the highest design storage pressure of the storage gas cylinder is not lower than the critical pressure of hydrogen, and the current pressure does not exceed the highest design storage pressure.

9. A system for determining a supercritical hydrogen storage state, characterized in that: The storage cylinder suitable for storing the supercritical hydrogen is a low-temperature high-pressure container; the system comprises: A data acquisition module, used to collect the current temperature and current pressure in the storage gas cylinder; A density calculation module, used to calculate the current density of the supercritical hydrogen in the storage cylinder according to the current temperature and the current pressure; wherein the supercritical hydrogen has a maximum storage density when stored in the storage cylinder; A filling rate determination module, used to obtain the current filling rate of the storage cylinder according to the comparison result between the current density and the maximum storage density; wherein the current filling rate is used to characterize the storage state of supercritical hydrogen in the storage cylinder; A storage state determination module is used to compare the current filling rate with the safety threshold range of the storage gas cylinder to determine the storage state of supercritical hydrogen in the storage gas cylinder; wherein the safety threshold range is determined by the filling rate when the storage gas cylinder is in a normal state.

10. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method for determining the supercritical hydrogen storage state according to any one of claims 1 to 8 by executing the computer instructions.

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