Detection method and detection system for liquid hydrogen evaporation rate of liquid hydrogen container

Abstract

The liquid hydrogen evaporation rate detection method of the liquid hydrogen container comprises the following steps that the evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained through a flow detection method, and the evaporation rate is a first evaporation rate A; the evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained through a weighing detection method and serves as a second evaporation rate B; carrying out weight calculation on the first evaporation rate A and the second evaporation rate B to obtain a liquid hydrogen evaporation rate detection value alpha of the liquid hydrogen container; converting flow data detected by the flow detection method into a weight coefficient as a first weight coefficient M of the first evaporation rate A; converting weighing data detected by the weighing detection method into a weight coefficient as a second weight coefficient M of the second evaporation rate B; the liquid hydrogen evaporation rate alpha is obtained according to the sum of the product of the first evaporation rate A and the first weight coefficient M and the product of the second evaporation rate B and the second weight coefficient N; a standard flow detection method and a weighing detection method are combined to comprehensively obtain a liquid hydrogen evaporation rate detection value of the liquid hydrogen container, and the detection value can reflect the actual evaporation rate of the liquid hydrogen container.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid hydrogen storage, and in particular, relates to a liquid hydrogen evaporation rate detection method and a monitoring system for a liquid hydrogen container. Background Art

[0002] With the development of hydrogen energy, more advanced liquid hydrogen storage containers are needed. The performance requirements of liquid hydrogen storage containers mainly include: meeting storage pressure, thermal insulation and safety. Among them, thermal insulation is one of the most important indicators. The thermal insulation performance of the container is usually measured by evaporation rate test.

[0003] At present, the main methods for detecting the evaporation rate of liquid hydrogen containers are the flow detection method and weighing detection method specified in the national standard, which are applicable to vacuum insulated liquid hydrogen containers. There is no method for measuring the evaporation rate of stacked insulated liquid hydrogen containers, nor is there a method for combining the flow detection method and the weighing detection method to obtain the final liquid hydrogen container evaporation rate detection value. Although the flow detection method and the weighing detection method can respectively reflect the liquid hydrogen evaporation rate of the liquid hydrogen container from the flow outflow or weight loss, for stacked insulated liquid hydrogen containers, the evaporation volume is relatively large, the flow resistance is large, and the measurement accuracy error of the flow detection method is large. There is also a certain error in relying solely on the weighing detection method, resulting in the detection value being inaccurate and unable to fully reflect the actual liquid hydrogen evaporation rate of the liquid hydrogen container.

[0004] Therefore, the standard flow detection method and weighing detection method are combined to comprehensively obtain the liquid hydrogen evaporation rate detection value of the liquid hydrogen container. The detection result is more accurate and can better reflect the actual liquid hydrogen evaporation rate of the liquid hydrogen container. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a liquid hydrogen evaporation rate detection method and a detection system for a liquid hydrogen container. By combining a standard flow detection method and a weighing detection method, a liquid hydrogen evaporation rate detection value of the liquid hydrogen container is comprehensively obtained, so that the liquid hydrogen evaporation rate detection value of the liquid hydrogen container is closer to the actual evaporation rate of the liquid hydrogen container.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0007] A method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container comprises the following steps:

[0008] The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by using a flow detection method, which is a first evaporation rate A;

[0009] The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by a weighing detection method, which is the second evaporation rate B;

[0010] The first evaporation rate A and the second evaporation rate B are weighted to obtain a liquid hydrogen evaporation rate detection value α of the liquid hydrogen container.

[0011] Furthermore, the weighted calculation of the first evaporation rate A and the second evaporation rate B to obtain the liquid hydrogen evaporation rate detection value α of the liquid hydrogen container specifically includes the following:

[0012] The flow rate data detected by the flow rate detection method is converted into a weight coefficient as a first weight coefficient M of the first evaporation rate A;

[0013] The weighing data detected by the weighing detection method is converted into a weight coefficient as a second weight coefficient M of the second evaporation rate B;

[0014] The liquid hydrogen evaporation rate detection value α is obtained according to the sum of the product of the first evaporation rate A and the first weight coefficient M and the product of the second evaporation rate B and the second weight coefficient N.

[0015] Further, the flow data detected by the flow detection method includes the uncertainty m of the flow detection method estimated based on the data detected by the flow detection method;

[0016] The weighing data detected by the weighing detection method includes the uncertainty n of the weighing detection method estimated based on the data detected by the weighing detection method;

[0017] Determine a first weight coefficient M based on the weight ratio of the uncertainty m of the flow detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, M=m / m+n;

[0018] The second weight coefficient N is determined based on the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, N=n / m+n.

[0019] Furthermore, the uncertainty m of the flow detection method estimated based on the data detected by the flow detection method includes at least the data detected by the flow meter calibration unit corresponding to the first uncertainty u FB1 , the second uncertainty u corresponding to the flow meter calibration unit and the added medium unit FB2 , the third uncertainty u corresponding to the data calibration unit FA2 ;

[0020] For the first uncertainty u FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 The flow uncertainty m is obtained by performing RMS calculation.

[0021] Furthermore, the uncertainty n of the weighing detection method estimated based on the data detected by the weighing detection method includes at least the first uncertainty u corresponding to the weighing instrument calibration unit. WB1, the second uncertainty u corresponding to the measured value of the absolute pressure transmitter WB2 , the third uncertainty u corresponding to environmental factors WB3 , the fourth uncertainty u corresponding to time measurement WB4 , the fifth uncertainty u corresponding to the data acquisition device WA2 ,

[0022] For the first uncertainty u WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 、The fifth uncertainty u WA2 The uncertainty n of the weighing method is obtained by performing RMS calculation.

[0023] Further, according to the weight ratio of the uncertainty m of the flow detection method in the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain a first weight coefficient M;

[0024] According to the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain the second weight coefficient N.

[0025] Furthermore, the uncertainty m of the flow detection method is based on the first uncertainty u of the flow detection method detection FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty m of the flow detection method is obtained;

[0026] The first uncertainty u of the weighing method based on the uncertainty n of the weighing method WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 , the fifth uncertainty u WA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty n of the weighing detection method is obtained.

[0027] A liquid hydrogen evaporation rate detection system for a liquid hydrogen container, comprising:

[0028] A first detection module includes a discharge pipeline connected to the liquid hydrogen container, and a flow meter is provided on the discharge pipeline for measuring the amount of the medium discharged from the discharge pipeline and obtaining a first evaporation rate A according to the measured value;

[0029] The second detection module includes a hoisting platform for placing the liquid hydrogen container. A weighing sensor is arranged on the hoisting platform for weighing and measuring the liquid hydrogen container and obtaining a second evaporation rate B according to the measured value.

[0030] Furthermore, it also includes a liquid hydrogen filling source, which is connected to the liquid hydrogen container via a filling pipeline and is used to inject liquid hydrogen into the liquid hydrogen container; the filling pipeline is provided with a filling valve for controllably opening and closing the pipeline.

[0031] Furthermore, it also includes a pressurizing source, which is connected to the liquid hydrogen container via a pressurizing pipeline and is used to inject a pressurized medium into the liquid hydrogen container; the pressurizing pipeline is provided with a pressurizing valve for controllably opening and closing the pipeline.

[0032] After adopting the above technical scheme, the present invention has the following beneficial effects compared with the prior art.

[0033] 1. Combine the flow detection method and the weighing detection method to measure the liquid hydrogen evaporation rate of the liquid hydrogen container to improve the credibility of the data. By verifying each other through two different detection methods, the error caused by the measurement accuracy of the flow detection method can be reduced, and the accuracy of the measurement results and the credibility of the data can be improved.

[0034] 2. By combining the data from the weighing detection method and the flow detection method, the evaporation rate of the stacked insulated liquid hydrogen container can be fully understood from the two aspects of mass loss and outflow rate, so that the liquid hydrogen evaporation rate detection value of the liquid hydrogen container is closer to the actual liquid hydrogen evaporation rate of the liquid hydrogen container.

[0035] 3. It is suitable for the needs of fast and accurate measurement of liquid hydrogen evaporation rate in practical engineering applications. The combination of standard flow detection method and weighing detection method improves data credibility and provides a more complete method for measuring the evaporation rate of liquid hydrogen containers.

[0036] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings:

[0038] Figure 1 It is a flow chart of a method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container of the present invention;

[0039] Figure 2 is a schematic diagram of a liquid hydrogen container of the present invention;

[0040] Explanation of the numbers in the figure: 1. Liquid hydrogen container; 2. Container lifting platform; 3. Weighing sensor; 4. Leveling steel plate; 5. Filling port; 52. Filling pipeline; 6. Discharge port; 61. Discharge pipeline; 62. Discharge valve; 7. Liquid level gauge; 8. Booster port; 81. Absolute pressure transmitter; 82. Booster valve; 83. Booster pipeline; 10. Sampling port; 11. Discharge tower; 12. Flow meter; 13. Flow meter valve.

[0041] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0043] In the description of the present invention, it should be noted that the terms "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "contacted", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] The present invention provides a method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container, which uses a volume flowmeter or a mass flowmeter to measure the natural evaporation amount of liquid hydrogen in the liquid hydrogen container per unit time, or uses a weighing detection method to measure the loss amount of liquid hydrogen per unit time.

[0046] The following steps are included:

[0047] The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by using a flow detection method, which is a first evaporation rate A;

[0048] The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by a weighing detection method, which is the second evaporation rate B;

[0049] The first evaporation rate A and the second evaporation rate B are weighted to obtain a liquid hydrogen evaporation rate detection value α of the liquid hydrogen container.

[0050] Weighing test method:

[0051] The weighing sensor is used to weigh the liquid hydrogen container at regular intervals and record the weight change of the liquid hydrogen container.

[0052] The mass loss of liquid hydrogen can be obtained by continuous weighing, thereby calculating the first evaporation rate A.

[0053] Flow detection method:

[0054] A flow meter is set on the discharge pipeline of the liquid hydrogen container to measure the amount of gas flowing out.

[0055] Through the gas flow rate, the outflow of liquid hydrogen per unit time can be calculated, thereby calculating the second evaporation rate B.

[0056] By combining the weighing detection method and the flow detection method, a more accurate liquid hydrogen evaporation rate can be obtained.

[0057] By using the weighing detection method and the flow detection method to verify the results, the accuracy of the measurement can be verified, possible errors can be eliminated, and the credibility of the measurement results can be improved. At the same time, through multi-faceted data collection and analysis, a more comprehensive understanding of the evaporation of liquid hydrogen can be obtained, providing more accurate data support for practical applications.

[0058] The weighing detection method also specifically includes calculating the evaporation rate by measuring the weight change of liquid hydrogen in the liquid hydrogen container over a period of time. The total weight of the liquid hydrogen in the liquid hydrogen container in the initial state is recorded. The specific method of obtaining the weight of the liquid hydrogen is as follows: after the liquid hydrogen is filled, the total weight of the liquid hydrogen container and the liquid hydrogen in the liquid hydrogen container is measured and the weight of the liquid hydrogen is subtracted from the weight of the liquid hydrogen container; after the set time is reached, the weight of the liquid hydrogen in the liquid hydrogen container is measured and recorded, and the evaporation amount of the liquid hydrogen is calculated based on the current weight.

[0059] By regularly weighing with weighing equipment, the mass changes of liquid hydrogen can be recorded.

[0060] The weighted calculation of the first evaporation rate A and the second evaporation rate B to obtain the liquid hydrogen evaporation rate detection value α of the liquid hydrogen container specifically includes the following steps: converting the flow data detected by the flow detection method into a weight coefficient as a first weight coefficient M of the first evaporation rate A;

[0061] The weighing data detected by the weighing detection method is converted into a weight coefficient as a second weight coefficient M of the second evaporation rate B;

[0062] The liquid hydrogen evaporation rate α is obtained according to the sum of the product of the first evaporation rate A and the first weight coefficient M and the product of the second evaporation rate B and the second weight coefficient N.

[0063] The flow rate data detected by the flow rate detection method includes the uncertainty m of the flow rate detection method estimated based on the data detected by the flow rate detection method;

[0064] The weighing data detected by the weighing detection method includes the uncertainty n of the weighing detection method estimated based on the data detected by the weighing detection method;

[0065] Determine a first weight coefficient M based on the weight ratio of the uncertainty m of the flow detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, M=m / m+n;

[0066] The second weight coefficient N is determined based on the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, N=n / m+n.

[0067] For the measurement value of the flow detection method, the uncertainty needs to be estimated based on the corresponding standard degrees of freedom. The standard degrees of freedom is one of the important parameters for evaluating the uncertainty of the measurement results. The uncertainty of the flow detection method measurement value is calculated through the possible sources of error in the actual measurement. The sources of error include:

[0068] The data detected by the flow detection method in the flow detection method uncertainty m includes at least the first uncertainty corresponding to the flow meter calibration unit: when the flow meter is calibrated in the measurement department, the calibration uncertainty u FB1 , the corresponding degrees of freedom are v FB1 ;

[0069] The second uncertainty u corresponding to the flow meter calibration unit and the added medium unit FB2 , the corresponding degrees of freedom are v FB2 ,

[0070] The third uncertainty u corresponding to the data calibration unit FA2 , the corresponding degrees of freedom are v FA2 ,

[0071] For the first uncertainty u FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 Perform RMS calculation to determine the uncertainty m of the flow detection method.

[0072] The uncertainty n of the weighing detection method is based on the data detected by the weighing detection method, including at least the first uncertainty u corresponding to the weighing instrument calibration unit. WB1 , the second uncertainty u corresponding to the measured value of the absolute pressure transmitter WB2 , the third uncertainty u corresponding to the environmental factor WB3, the fourth uncertainty u corresponding to time measurement WB4 , the fifth uncertainty u corresponding to the data acquisition device WA2 ;

[0073] For the first uncertainty u WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 , the fifth uncertainty u WA2 The uncertainty n of the weighing method is obtained by performing RMS calculation.

[0074] The influencing factors mentioned above may specifically include the following aspects:

[0075] Temperature: The temperature of liquid hydrogen directly affects its density and evaporation rate, thus affecting the uncertainty.

[0076] Pressure: The pressure of liquid hydrogen affects its density and vaporization temperature, which in turn affects the uncertainty.

[0077] Container: The material, thickness, shape and other factors of the liquid hydrogen storage container will also affect its uncertainty.

[0078] Environmental conditions: Environmental conditions such as atmospheric pressure, temperature, and humidity will also have a certain impact on the uncertainty of liquid hydrogen.

[0079] The standard degrees of freedom corresponding to the data measured by the weighing method can be used to estimate the uncertainty of the results measured by the weighing method. Taking into account the possible sources of error in the weighing process, the uncertainty of the measured value of the weighing method can be calculated to ensure the reliability of the measurement results.

[0080] When estimating uncertainty, it is necessary to consider factors such as the accuracy of the measuring equipment, the influence of environmental conditions, and the technical level of the operator to ensure an accurate estimate of uncertainty.

[0081] Working principle: The first evaporation rate A is obtained by flow detection method. Unit: kg / d; where:

[0082] Q e - Average mass flow rate of evaporated hydrogen within 24 hours, kg / d;

[0083] ρ-density of saturated liquid under standard atmospheric pressure (101.325kPa), kg / m 3 ;

[0084] Gas density at standard atmospheric pressure 273.15K, kg / m 3 .

[0085] V-effective volume of the inspected object, m 3 ;

[0086] The second evaporation rate B obtained by weighing detection method, Unit, kg / d; where,

[0087] Q g -Mass of hydrogen evaporated within 24 hours, kg / d;

[0088] ρ-density of saturated liquid under standard atmospheric pressure (101.325kPa), kg / m 3 ;

[0089] V-effective volume of the inspected object, m 3 ;

[0090] The evaporation rate of liquid hydrogen in the liquid hydrogen container is,

[0091]

[0092] The ratio of the first weight coefficient M to the second weight coefficient N can be different, and can be 0.6:0.4, 0.3:0.7, or can be the same, for example, 0.5:0.5.

[0093] Uncertainty refers to the degree of uncertainty about the measured value due to the existence of measurement errors, that is, it can indicate the reliability of the result. The smaller the uncertainty, the higher the quality, the higher the level, and the higher the use value; in the present invention, the smaller the uncertainty and the lower the evaporation rate, the better the performance of the liquid hydrogen container.

[0094] The measurement results need to be evaluated using measurement uncertainty. The smaller the measurement uncertainty, the higher the reliability of the measurement results.

[0095] Comparison of the degrees of freedom indicates the degree of confidence in the given measurement uncertainty.

[0096] Uncertainty and degrees of freedom are both related to the reliability of data measurement results. In the actual measurement process, the degrees of freedom of the sample will affect the size of the calculated uncertainty. An increase in degrees of freedom usually reduces the uncertainty of the measurement results because more degrees of freedom provide more reliability and precision.

[0097] like Figure 2 As shown, the liquid hydrogen evaporation rate detection system of the liquid hydrogen container includes a first detection module, a second detection module, and a liquid hydrogen filling module, which are used to measure the liquid hydrogen evaporation rate of the liquid hydrogen container 1. The liquid hydrogen container 1 includes a filling port 5, a discharge port 6, and a pressurization port 8.

[0098] Specifically, the first detection module includes a discharge pipeline 61 and a flow meter 12, including the flow meter 12 and the discharge pipeline 61, one end of the discharge pipeline 61 is installed with the flow meter 12, and the other end is connected to the discharge port 6 of the liquid hydrogen container 1, so as to use the first detection module to adopt a flow detection method to detect the liquid hydrogen evaporation rate of the liquid hydrogen container to obtain a first detection value A; the second detection module includes a container lifting platform 2, a group of weighing sensors 3 are arranged on both sides of the container lifting platform 2, and a group of leveling steel plates 4 are also arranged on both sides of the container lifting platform 2, so as to use the second detection module to adopt a weight detection method to detect the liquid hydrogen evaporation rate of the liquid hydrogen container to obtain a second detection value B.

[0099] The filling source is controlled to fill liquid hydrogen into the liquid hydrogen container, and the weight detection value of the liquid hydrogen in the liquid hydrogen container 1 is obtained through the weighing sensor 3; after the set time is reached, the weight detection value of the liquid hydrogen in the liquid hydrogen container 1 is obtained again through the weighing sensor 3, and the changes in the weight detection values ​​at different times are obtained to realize the second detection value B obtained by detecting the evaporation rate of the liquid hydrogen in the liquid hydrogen container by the weight detection method; and / or, after the set time is reached, the flow detection value of the liquid hydrogen flowing through the discharge pipeline 61 within the set time is obtained by the flow meter 12 to realize the first detection value A obtained by detecting the evaporation rate of the liquid hydrogen in the liquid hydrogen container by the flow detection method.

[0100] Specifically, the liquid hydrogen filling module includes a filling pipeline 52, one end of the filling pipeline 52 is connected to the filling port 5 of the liquid hydrogen container 1, and the other end is connected to the filling unit; liquid hydrogen is injected into the liquid hydrogen container 1 from the filling pipeline 52 through the liquid hydrogen filling module, and the liquid level meter 7 monitors the liquid level changes in the liquid hydrogen container 1.

[0101] Specifically, the liquid hydrogen evaporation rate detection system of the liquid hydrogen container also includes a pressure regulating module, which includes a boosting pipeline 83, on which a boosting valve 82 and an absolute pressure transmitter 81 are arranged, one end of the boosting pipeline 83 is connected to the boosting port 8 of the liquid hydrogen container 1, and the other end is connected to the pressurizing unit, and the absolute pressure transmitter 81 is arranged between the boosting port 8 and the boosting valve 82. The pressure regulating module controls the pressure in the liquid hydrogen container 1 to ensure that the pressure inside the liquid hydrogen container 1 is maintained within a specified range; the absolute pressure transmitter 81 is used to measure the absolute pressure of the medium, that is, the pressure value relative to the vacuum, and the gas after pressure regulation passes through the discharge pipeline 61 and is discharged through the discharge tower 11.

[0102] The liquid hydrogen filling source may be a filling tank, and the pressurizing source includes a boost valve 82 .

[0103] Adjust the leveling device to make the whole system in a horizontal state, eliminate the weight of the container, and improve the accuracy of the weighing instrument measurement; set a gas flow meter on the main discharge pipeline at the end of the system to measure the flow of the evaporated gas medium. The flow meter can also be a mass flow meter, sampling through the sampling port 10, detecting the mass change of the liquid hydrogen in the liquid hydrogen container, and then obtaining the first evaporation rate A of the liquid hydrogen container through the flow detection method.

[0104] According to the weight ratio of the uncertainty m of the flow detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain a first weight coefficient M;

[0105] According to the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain the second weight coefficient N.

[0106] When adding revision values, it is necessary to consider temperature difference, pressure difference, time period, container shape and material, environmental conditions, etc. Among them, temperature difference refers to the temperature difference between the body and the surrounding environment; pressure difference refers to the difference between the pressure inside and outside the container; time period refers to the time taken in the measurement process; container shape and material will have a certain impact on the evaporation rate; environmental conditions include atmospheric pressure, etc.

[0107] Since liquid hydrogen is in liquid state at low temperatures, accurate measurement of its evaporation rate needs to take into account many factors, such as ambient temperature, pressure, and container material.

[0108] The two different measurement methods are used to verify each other and reduce the possible errors of a single method. At the same time, by combining the flow detection method and the weighing detection method, measurements can be performed under different conditions to better meet different experimental needs.

[0109] The first uncertainty u of the flow detection method based on the uncertainty m of the flow detection method FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty m of the flow detection method is obtained;

[0110] The first uncertainty u of the weighing method based on the uncertainty n of the weighing method WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 , the fifth uncertainty u WA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty n of the weighing detection method is obtained.

[0111] The main purpose of calculating the evaporation rate of liquid hydrogen is to evaluate the safety performance of liquid hydrogen storage tanks. Liquid hydrogen is an extremely low-temperature liquid at room temperature, which will continue to evaporate to produce hydrogen. If the evaporation rate of liquid hydrogen cannot be controlled during storage, it may cause the gas pressure in the storage tank to be too high, causing an explosion or other safety accidents. Therefore, by calculating the evaporation rate of liquid hydrogen, we can better understand the changes in the hydrogen pressure in the storage tank, so as to formulate more scientific safety measures to ensure the safety of the liquid hydrogen storage process.

[0112] Measure the flow rate and weight of liquid hydrogen before entering the liquid hydrogen container,

[0113] After the set time is reached, measure the weight of the liquid hydrogen in the liquid hydrogen container again.

[0114] Through the degree of freedom, uncertainty detection is carried out on the liquid hydrogen environment.

[0115] Changes in weight reflect changes in flow.

[0116] The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by calculating the evaporation rate of the gas passing through the exhaust port of the liquid hydrogen container.

[0117] Weighted averaging according to uncertainty weights can improve the accuracy and reliability of the comprehensive uncertainty and provide a more scientific and comprehensive basis for the analysis and application of the measurement results of the evaporation rate of liquid hydrogen containers.

[0118] Through the above-mentioned settings, the detection system of the present application can combine the weighing sensor data using the weight detection method to detect the liquid hydrogen evaporation rate of the liquid hydrogen container to obtain the second evaporation rate B, and the flow meter data using the flow detection method to detect the liquid hydrogen evaporation rate of the liquid hydrogen container to obtain the first evaporation rate A, and comprehensively obtain the liquid hydrogen evaporation rate detection value α of the liquid hydrogen container.

[0119] The pressure of the liquid hydrogen container is tested through the pressure regulating module and adjusted to the preset pressure value. After the set time is reached, the pressure is tested again to adjust the pressure value in the liquid hydrogen container to the preset pressure value. During the two tests, the pressure value in the liquid hydrogen container needs to be kept at the same pressure value. If there is gas outflow during the adjustment process, the flow rate of the outflowing gas is tested.

[0120] Pressure detection includes determining whether the liquid hydrogen filling amount reaches the set amount, whether the liquid hydrogen concentration reaches the set concentration value, and whether the pressure value in the liquid hydrogen container reaches the set pressure value. The pressure detection value is determined based on the filling amount, concentration value, and pressure value. If at least one pressure detection value does not meet the standard, the pressure detection value is adjusted before starting the detection.

[0121] After the liquid hydrogen container is filled with liquid hydrogen, it is left to stand for at least 48 hours, and the time intervals for recording the first evaporation rate A and the second evaporation rate B are at least 24 hours and 48 hours.

[0122] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the present invention can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container, characterized in that: The following steps are included: The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by using a flow detection method, which is a first evaporation rate A; The evaporation rate of liquid hydrogen in the liquid hydrogen container is obtained by a weighing detection method, which is the second evaporation rate B; The first evaporation rate A and the second evaporation rate B are weighted to obtain a liquid hydrogen evaporation rate detection value α of the liquid hydrogen container.

2. The method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claim 1, characterized in that: The weighted calculation of the first evaporation rate A and the second evaporation rate B to obtain the liquid hydrogen evaporation rate detection value α of the liquid hydrogen container specifically includes the following: The flow rate data detected by the flow rate detection method is converted into a weight coefficient as a first weight coefficient M of the first evaporation rate A; The weighing data detected by the weighing detection method is converted into a weight coefficient as a second weight coefficient M of the second evaporation rate B; The liquid hydrogen evaporation rate detection value α is obtained according to the sum of the product of the first evaporation rate A and the first weight coefficient M and the product of the second evaporation rate B and the second weight coefficient N.

3. The method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claim 2, characterized in that: The flow rate data detected by the flow rate detection method includes the uncertainty m of the flow rate detection method estimated based on the data detected by the flow rate detection method; The weighing data detected by the weighing detection method includes the uncertainty n of the weighing detection method estimated based on the data detected by the weighing detection method; Determine a first weight coefficient M based on the weight ratio of the uncertainty m of the flow detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, M=m / m+n; The second weight coefficient N is determined based on the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, N=n / m+n.

4. The method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claim 3, characterized in that: The uncertainty m of the flow detection method estimated based on the data detected by the flow detection method includes at least the data detected by the flow detection method, the first uncertainty u corresponding to the flow meter calibration unit FB1 , the second uncertainty u corresponding to the flow meter calibration unit and the added medium unit FB2 , the third uncertainty u corresponding to the data calibration unit FA2 ; For the first uncertainty u FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 The flow uncertainty m is obtained by performing RMS calculation.

5. The method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claim 3, characterized in that: The uncertainty n of the weighing detection method estimated based on the data detected by the weighing detection method is based on the data detected by the weighing detection method including at least the first uncertainty u corresponding to the weighing instrument calibration unit. WB1 , the second uncertainty u corresponding to the measured value of the absolute pressure transmitter WB2 , the third uncertainty u corresponding to environmental factors WB3 , the fourth uncertainty u corresponding to time measurement WB4 , the fifth uncertainty u corresponding to the data acquisition device WA2 , For the first uncertainty u WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 , the fifth uncertainty u WA2 The uncertainty n of the weighing detection method is obtained by performing RMS calculation.

6. The method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claim 3, characterized in that: According to the weight ratio of the uncertainty m of the flow detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain a first weight coefficient M; According to the weight ratio of the uncertainty n of the weighing detection method to the sum of the uncertainty m of the flow detection method and the uncertainty n of the weighing detection method, a correction coefficient is added to obtain the second weight coefficient N.

7. A method for detecting the evaporation rate of liquid hydrogen in a liquid hydrogen container according to claims 4 and 5, characterized in that: The first uncertainty u of the flow detection method based on the uncertainty m of the flow detection method FB1 , the second uncertainty u FB2 , the third uncertainty u FA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty m of the flow detection method is obtained; The first uncertainty u of the weighing method based on the uncertainty n of the weighing method WB1 , the second uncertainty u WB2 , the third uncertainty u WB3 、The fourth uncertainty u WB4 , the fifth uncertainty u WA2 , add the calibration values ​​respectively, and substitute the calibration values ​​into the above formula The uncertainty n of the weighing detection method is obtained.

8. A liquid hydrogen evaporation rate detection system using the liquid hydrogen container according to any one of claims 1 to 7, characterized in that: include, A first detection module includes a discharge pipeline connected to the liquid hydrogen container, and a flow meter is provided on the discharge pipeline for measuring the amount of the medium discharged from the discharge pipeline and obtaining a first evaporation rate A according to the measured value; The second detection module includes a hoisting platform for placing the liquid hydrogen container. A weighing sensor is arranged on the hoisting platform for weighing and measuring the liquid hydrogen container and obtaining a second evaporation rate B according to the measured value.

9. A liquid hydrogen evaporation rate detection system for a liquid hydrogen container according to claim 8, characterized in that: It also includes a liquid hydrogen filling source, which is connected to the liquid hydrogen container via a filling pipeline and is used to inject liquid hydrogen into the liquid hydrogen container; a filling valve for controllably opening and closing the pipeline is provided on the filling pipeline.

10. A liquid hydrogen evaporation rate detection system for a liquid hydrogen container according to claim 8, characterized in that: It also includes a pressurizing source, which is connected to the liquid hydrogen container via a pressurizing pipeline and is used to inject a pressurized medium into the liquid hydrogen container; a pressurizing valve is provided on the pressurizing pipeline for controllably opening and closing the pipeline.

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