Evaporation rate dynamic monitoring method and system for stationary cryogenic storage tank

Abstract

The present application relates to the technical field of low-temperature storage tank, in particular to a kind of evaporation rate dynamic monitoring method and system for static low-temperature storage tank, by obtaining the monitoring data of different liquid level in low-temperature storage tank, monitoring data includes steam concentration data, and airflow velocity data, air pressure data and liquid level monitoring data at different sampling positions;Analysis of monitoring data, determine the steam diffusion rate under different liquid level, and combine the change of liquid level data under different liquid level, determine the influence factor of airflow disturbance on evaporation rate under different liquid level, so as to correct the initial estimated evaporation rate under different liquid level based on the influence factor of airflow disturbance on evaporation rate.The present application corrects the initial estimated evaporation rate by analyzing the influence of airflow disturbance on evaporation rate under different liquid level, effectively improves the accuracy of low-temperature storage tank evaporation rate dynamic monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low-temperature storage tanks, in particular to a kind of evaporation rate dynamic monitoring method and system for static low-temperature storage tank. BACKGROUND

[0002] Low-temperature storage tank is a kind of equipment for storing low-temperature liquid or gas, which is usually used to store liquid with boiling point lower than normal temperature, such as liquid nitrogen, liquid oxygen, liquid helium, etc., and is widely used in industry, medical treatment, scientific research and other fields. Since the low-temperature liquid will evaporate due to temperature change, external environment change and other reasons during storage, and may cause the failure of the storage tank or cause resource waste, it is particularly important to dynamically monitor the evaporation rate of the low-temperature storage tank.

[0003] In the prior art, the evaporation rate of the low-temperature storage tank is usually determined by coupling and estimating multiple source monitoring data. However, since the liquid level is an important factor affecting the evaporation rate, the liquid in the low-temperature storage tank has different degrees of airflow pressure and liquid level fluctuation at different liquid levels. Under the interference of this important factor, the real-time evaporation rate monitoring result will have greater deviation with the change of the liquid level, thereby affecting the accuracy of evaporation rate monitoring and early warning. SUMMARY

[0004] In order to solve the above technical problems, the purpose of the present application is to provide a kind of evaporation rate dynamic monitoring method and system for static low-temperature storage tank, the technical scheme adopted is as follows:

[0005] In the first aspect, the present application provides a kind of evaporation rate dynamic monitoring method for static low-temperature storage tank, comprising the following steps:

[0006] Obtain monitoring data at different liquid levels inside the low-temperature storage tank, the monitoring data includes steam concentration data, and airflow velocity data, air pressure data and liquid level monitoring data at different sampling positions;

[0007] Analyze the change of airflow velocity data and air pressure data at different sampling positions at different liquid levels to determine the airflow interference degree at different liquid levels;

[0008] Determine the steam diffusion rate at different liquid levels based on the airflow interference degree at different liquid levels and the distribution of steam concentration data;

[0009] Determine the influence factor of airflow disturbance on evaporation rate at different liquid levels based on the steam diffusion rate and the change of liquid level data at different liquid levels;

[0010] Correct the initial estimated evaporation rate under different liquid surface heights based on the influence factor of the airflow disturbance on the evaporation rate to obtain a corrected evaporation rate under different liquid surface heights.

[0011] In combination with the first aspect, in some possible implementation manners, determining the airflow disturbance degree under different liquid surface heights comprises:

[0012] Determining the airflow velocity unevenness under different liquid surface heights based on a difference distribution between airflow velocity data at different sampling positions under different liquid surface heights;

[0013] Determining the air pressure difference degree under different liquid surface heights based on a difference size between air pressure data at different sampling positions under different liquid surface heights;

[0014] Fusing the airflow velocity unevenness and the air pressure difference degree to determine the airflow disturbance degree under different liquid surface heights.

[0015] In combination with the first aspect, in some possible implementation manners, determining the airflow velocity unevenness under different liquid surface heights comprises:

[0016] In the airflow velocity data at different sampling positions under different liquid surface heights, determining an airflow velocity mean value at each moment based on a distribution level of the airflow velocity at different sampling positions at each moment;

[0017] Determining an airflow velocity difference at each moment based on a difference size between the airflow velocity at different sampling positions at each moment and the airflow velocity mean value;

[0018] Determining the airflow velocity unevenness under different liquid surface heights based on a difference between airflow velocity differences at different moments under different liquid surface heights.

[0019] In combination with the first aspect, in some possible implementation manners, determining the air pressure difference degree under different liquid surface heights comprises:

[0020] In the air pressure data at different sampling positions under different liquid surface heights, determining an air pressure range corresponding to the air pressure at different sampling positions at each moment;

[0021] Determining the air pressure difference degree under different liquid surface heights based on a distribution level of air pressure ranges at different moments under different liquid surface heights.

[0022] In combination with the first aspect, in some possible implementation manners, determining the vapor diffusion rate under different liquid surface heights comprises:

[0023] Determining a relative vapor concentration under different liquid surface heights based on a difference between vapor concentration data under different liquid surface heights and a vapor concentration in an initial full-tank state;

[0024] Determine the vapor diffusion rate at different liquid levels based on the airflow disturbance degree and the relative vapor concentration at different liquid levels.

[0025] In combination with the first aspect, in some possible implementation manners, determining the influence factor of the airflow disturbance on the evaporation rate at different liquid levels comprises:

[0026] Determine the liquid level fluctuation degree at different liquid levels based on the difference between the liquid level monitoring data of different sampling points at different liquid levels;

[0027] Fuse the vapor diffusion rate and the liquid level fluctuation degree to determine the influence factor of the airflow disturbance on the evaporation rate at different liquid levels.

[0028] In combination with the first aspect, in some possible implementation manners, determining the liquid level fluctuation degree at different liquid levels comprises:

[0029] Determine the maximum height value and the minimum height value respectively in the liquid level monitoring data of all different sampling positions at different liquid levels, and the height difference value of the liquid level monitoring values of any two sampling positions at the same time;

[0030] Determine the liquid level fluctuation degree based on the distribution level of the height difference values corresponding to all sampling points at all times;

[0031] Determine the liquid level fluctuation degree at different liquid levels based on the maximum height value and the minimum height value at different liquid levels and the liquid level fluctuation degree.

[0032] In combination with the first aspect, in some possible implementation manners, correcting the initial estimated evaporation rate at different liquid levels based on the influence factor comprises:

[0033] Normalize the influence factor to obtain a modification parameter;

[0034] Determine the addition value of the modification parameter and a set value to obtain an evaporation rate correction coefficient;

[0035] Determine the product of the evaporation rate correction coefficient and the initial estimated evaporation rate at different liquid levels to obtain the corrected evaporation rate at different liquid levels.

[0036] In combination with the first aspect, in some possible implementation manners, the method further comprises: predicting the abnormal leakage condition of the low-temperature storage tank based on the corrected evaporation rate.

[0037] Secondly, the application further provides a dynamic evaporation rate monitoring device for a static low-temperature storage tank, which comprises:

[0038] a monitoring data acquisition module configured to acquire monitoring data at different liquid levels in the cryogenic tank, the monitoring data comprising vapor concentration data, and airflow velocity data, air pressure data, and liquid level monitoring data at different sampling locations;

[0039] an airflow disturbance degree analysis module configured to analyze changes in the airflow velocity data and the air pressure data at the different sampling locations at different liquid levels, and determine airflow disturbance degrees at the different liquid levels;

[0040] a vapor diffusion rate analysis module configured to determine vapor diffusion rates at the different liquid levels based on the airflow disturbance degrees at the different liquid levels and distribution of the vapor concentration data;

[0041] an influence factor analysis module configured to determine influence factors of airflow disturbance on the evaporation rate at the different liquid levels based on the vapor diffusion rates and changes in the liquid level data at the different liquid levels;

[0042] an evaporation rate correction module configured to correct initial estimated evaporation rates at the different liquid levels based on the influence factors of airflow disturbance on the evaporation rate, to obtain corrected evaporation rates at the different liquid levels.

[0043] In a third aspect, the present application further provides a system for dynamically monitoring evaporation rates of a stationary cryogenic tank, comprising a memory and a processor. The memory is configured to store executable computer program code, and the processor is configured to call and run the executable computer program code from the memory, so that the system performs the method for dynamically monitoring evaporation rates of a stationary cryogenic tank in the first aspect or any possible implementation manner of the first aspect.

[0044] In a fourth aspect, the present application further provides a computer program product, which comprises computer program code. When the computer program code is run on a computer, the computer program code causes the computer to perform the method for dynamically monitoring evaporation rates of a stationary cryogenic tank in the first aspect or any possible implementation manner of the first aspect.

[0045] In a fifth aspect, the present application further provides a computer-readable storage medium, which stores computer program code. When the computer program code is run on a computer, the computer program code causes the computer to perform the method for dynamically monitoring evaporation rates of a stationary cryogenic tank in the first aspect or any possible implementation manner of the first aspect.

[0046] The present application has the following beneficial effects: the present application determines the air flow interference degree at different liquid levels by analyzing the air pressure and air flow change at different liquid levels in the tank, which is used to reflect the air flow disturbance at different liquid levels, then determines the vapor diffusion rate at different liquid levels based on the air flow disturbance of the liquid surface and the distribution of the vapor concentration data, which represents the influence of air flow interference on the liquid evaporation driving force; based on the vapor diffusion rate and the change of the liquid level data at different liquid levels, the influence degree of the liquid phase space air flow interference on the evaporation rate is analyzed, so as to determine the influence factor of the air flow disturbance on the evaporation rate at different liquid levels; finally, the initial estimated evaporation rate at different liquid levels is corrected based on the influence factor of the air flow disturbance on the evaporation rate, so as to solve the problem that the evaporation rate changes greatly with the liquid surface due to the change of air flow and liquid surface fluctuation at different liquid levels, thereby effectively improving the precision of the low-temperature tank evaporation rate monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, and the advantages thereof, hereinafter, a brief introduction will be given to the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0048] Figure 1 The step flow chart of the evaporation rate dynamic monitoring method for the static low-temperature tank of the embodiment of the present application;

[0049] Figure 2 The structural schematic diagram of the evaporation rate dynamic monitoring device for the static low-temperature tank of the embodiment of the present application;

[0050] Figure 3 The structural schematic diagram of the evaporation rate dynamic monitoring system for the static low-temperature tank of the embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to clearly illustrate the technical features of the present application, the present application will be described in detail below by specific implementation manners and in combination with the drawings.

[0052] The embodiments of the present application will be described in more detail below with reference to the drawings. Although some embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms, and should not be interpreted as being limited to the embodiments described herein, on the contrary, these embodiments are provided to make the present application more thorough and complete. It should be understood that the drawings and embodiments of the present application are only for exemplary purposes, and are not used to limit the protection scope of the present application.

[0053] It should be understood that each of the steps recited in the method embodiments of the present application can be performed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit performing the steps shown. The scope of the present application is not limited in this regard.

[0054] The term "comprising" and variations thereof as used herein are used inclusively, i.e., "comprising, but not limited to." The term "based on" is "based at least in part on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments." Related terms have corresponding meanings.

[0055] It should be noted that the terms "first", "second", and so on used in the present application are merely used to distinguish different devices, modules or units, and are not intended to limit the order or interdependence of the functions performed by these devices, modules or units.

[0056] In the embodiments of the present application, although the operations or steps are described in a particular order in the accompanying drawings, it should not be understood as requiring the operations or steps to be performed in the particular order or in a serial order, or requiring all of the shown operations or steps to be performed to obtain a desired result. In the embodiments of the present application, the operations or steps can be performed in series; the operations or steps can be performed in parallel; or a part of the operations or steps can be performed.

[0057] At the same time, it can be understood that the data involved in the technical solutions of the present application (including but not limited to the data itself, the acquisition or use of the data) should comply with the requirements of the corresponding laws, regulations and relevant provisions. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as understood by those skilled in the art to which the present application belongs, and all parameters or indicators in the formulas involved in the present application are normalized values that eliminate the dimension influence.

[0058] The method for dynamically monitoring the evaporation rate of a static low-temperature storage tank provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0059] Figure 1 The basic flowchart of the method for dynamically monitoring the evaporation rate of a static low-temperature storage tank provided by the embodiments of the present application is shown in FIG. 1, which specifically includes the following steps: Figure 1 As shown in FIG. 1, the method specifically includes the following steps:

[0060] Step S100: Obtain monitoring data at different liquid levels in the low-temperature storage tank, the monitoring data including vapor concentration data, and airflow flow rate data, air pressure data and liquid level monitoring data at different sampling positions.

[0061] Low-temperature storage tanks need to have good thermal insulation performance, and usually adopt multi-layer vacuum insulation technology (vacuum insulation layer) to reduce heat conduction, but the low-temperature liquid in it will evaporate due to temperature changes, changes in external environment and other reasons during storage. The evaporation rate refers to the mass of liquid evaporated from the low-temperature storage tank per unit time. For a stationary low-temperature storage tank, the evaporation rate is usually related to factors such as the external environment temperature of the storage tank, the internal pressure of the storage tank, the type of liquid, etc.

[0062] The liquid in the low-temperature storage tank will usually gradually decrease in liquid level height due to use and consumption, and the change in liquid level height in the storage tank has a significant impact on the evaporation rate, especially in low-temperature storage tanks (such as LNG, liquid nitrogen, and liquid oxygen storage tanks). Since the existing evaporation rate estimation method is determined under the premise that the airflow pressure and liquid surface fluctuation conditions are the same at different liquid level heights, there will be differences in the above factors as the liquid level height changes, which will cause errors in the estimation results of the evaporation rate.

[0063] Therefore, in order to improve the monitoring accuracy of the evaporation rate, the embodiments of the present application obtain monitoring data at different liquid level heights by deploying relevant sensors inside the low-temperature storage tank, and subsequently determine the influence factors of the evaporation rate at different liquid level heights by analyzing the monitoring data, thereby realizing accurate correction of the evaporation rate. The monitoring data includes vapor concentration data, airflow velocity data, air pressure data, and liquid level monitoring data at different sampling locations.

[0064] In the embodiments of the present application, a plurality of air pressure sensors and hot-wire anemometers are deployed inside the tank body of the low-temperature storage tank, and the air pressure sensors and hot-wire anemometers are used to collect a plurality of local real-time air pressure values and airflow velocity values at corresponding liquid level heights, with a sampling interval of 0.1 seconds. At the same time, a vapor concentration sensor is deployed inside the tank body of the low-temperature storage tank, and the vapor concentration sensor is used to collect vapor concentration values at different liquid level heights. In addition, the height information of the liquid surface is obtained based on laser ranging of the liquid surface, and the three-dimensional morphology of the liquid surface at the current liquid level height is modeled, and based on the modeling results of the three-dimensional morphology, liquid level monitoring data at different sampling locations at different liquid level heights is obtained. The vapor concentration data at different liquid level heights, the airflow velocity data and the air pressure data at different sampling locations, and the liquid level monitoring data together constitute the monitoring data inside the low-temperature storage tank at different liquid level heights. It should be understood that different liquid level heights refer to the corresponding liquid level heights of the liquid surface inside the low-temperature storage tank when the evaporation rate is detected, and the liquid level monitoring data refers to the actual liquid level values at different sampling locations obtained by laser ranging of the liquid surface.

[0065] Step S200: analyze the changes in the airflow velocity data and the air pressure data at different sampling locations at different liquid level heights to determine the airflow interference degree at different liquid level heights.

[0066] Because the liquid level in a cryogenic storage tank gradually decreases with use, changes in liquid level alter the disturbance effect of airflow on the liquid, leading to localized fluctuations at the gas-liquid interface. Larger fluctuations exacerbate the liquid evaporation process, thus affecting the measurement of the liquid evaporation rate within the tank. Therefore, this embodiment of the invention first calculates the corresponding liquid-airflow disturbance based on changes in gas pressure and airflow at the real-time liquid level, thereby determining the degree of airflow interference at different liquid level levels.

[0067] In this embodiment of the invention, step S200, determining the airflow disturbance at different liquid level heights, includes:

[0068] Step S201: Based on the difference distribution of airflow velocity data at different sampling locations under different liquid levels, determine the airflow velocity non-uniformity under different liquid levels.

[0069] Different liquid level heights typically have varying effects on evaporation rates. When the liquid level is low, airflow disturbances are more likely to cause local fluctuations on the liquid surface, making the airflow disturbances more pronounced and further increasing the evaporation rate. Conversely, when the liquid level is high, the gas phase space becomes smaller, the gas's buffering capacity weakens, the disturbance effect is weaker, and the evaporation rate error is generally smaller. Since the essence of airflow disturbance is the local non-uniform distribution of air pressure and airflow, the stronger the airflow disturbance, the greater the corresponding pressure imbalance and the more non-uniform the airflow velocity. Therefore, this study analyzes the difference distribution of airflow velocity data at different sampling locations under different liquid level heights to determine the airflow velocity non-uniformity at different liquid level heights.

[0070] In this embodiment of the invention, step S201, determining the non-uniformity of airflow velocity at different liquid levels, includes:

[0071] First, based on the distribution level of airflow velocity at different sampling locations under different liquid levels, the average airflow velocity at each sampling location is determined. Specifically, for the current liquid level... Calculate the height of this liquid level. Next The average airflow velocity at all sampling locations at the sampling time is used to obtain the th sampling moment. The average airflow velocity at each sampling time point is denoted as . .

[0072] Secondly, based on the difference between the airflow velocity at different sampling locations at each moment and the average airflow velocity, the airflow velocity difference at each moment is determined. Specifically, for the current liquid level... Calculate the height of this liquid level respectively. Next The airflow velocity at each sampling location at the sampling time and the... Average airflow velocity at each sampling time absolute value of the difference ,in, Therefore, the liquid level height is... At a certain sampling point at a sampling time The airflow velocity at point [number]. Then, the airflow velocity at point [number] is calculated. The absolute value of the difference at all sampling locations at each sampling time. The cumulative value is used to obtain the height of the liquid level at this point. Difference in airflow velocity at each sampling time ,in, Number of sampling locations. Difference in airflow velocity. Represents the first The relative difference in local airflow velocity at different sampling locations at each sampling time is represented by a value that indicates a greater difference and a more significant difference in local airflow velocity at that time.

[0073] Finally, based on the differences in airflow velocity at different times under different liquid levels, the non-uniformity of airflow velocity at different liquid levels is determined. Specifically, for the current liquid level... Calculate the height of this liquid level. Differences in airflow velocity at all sampling times The standard deviation is used as the height of the liquid surface. The standard deviation indicates the non-uniformity of airflow velocity. The larger the standard deviation, the greater the variation in airflow velocity at different sampling times, and the more non-uniform the airflow velocity.

[0074] Step S202: Determine the degree of pressure difference at different liquid levels based on the difference between the air pressure data at different sampling locations under different liquid levels.

[0075] Since airflow interference is often related to pressure imbalance, greater local pressure imbalance leads to airflow shifts and causes airflow interference. Therefore, the degree of pressure imbalance needs to be considered to more accurately measure the degree of airflow interference at this liquid level. Thus, the differences in pressure data at different sampling locations at different liquid levels are analyzed to determine the degree of pressure difference at different liquid levels.

[0076] In this embodiment of the invention, step S202, determining the pressure difference at different liquid levels, includes:

[0077] First, from the air pressure data at different sampling locations under different liquid levels, determine the pressure range corresponding to the air pressure at different sampling locations at each moment. Specifically, for the current liquid level... Calculate the height of this liquid level respectively. Next The maximum air pressure at different sampling locations at each sampling time. and minimum air pressure And calculate the maximum air pressure. and minimum air pressure The difference As the first The air pressure difference at each sampling time.

[0078] Secondly, based on the distribution level of the pressure difference at different times under different liquid levels, the pressure difference degree at different liquid levels is determined. Specifically, for the current liquid level... Calculate the pressure range at different sampling times. The average value is used to obtain the liquid level height. The degree of air pressure difference. The greater the air pressure range at different sampling times, the greater the corresponding air pressure difference, and the more likely it is to cause airflow disturbance.

[0079] Step S203: Combine the airflow velocity non-uniformity and air pressure difference to determine the airflow interference degree at different liquid level heights.

[0080] Simultaneously, by combining the airflow velocity non-uniformity and pressure difference at different liquid level heights, the airflow interference degree at different liquid level heights is determined. The greater the airflow velocity non-uniformity and the greater the pressure difference, the greater the airflow interference degree at that liquid level height, and the greater the impact of the airflow on the evaporation rate of the liquid surface. In this embodiment of the invention, for the current liquid level height... Calculate the product of the airflow velocity non-uniformity and the air pressure difference at this liquid level, and use this product as the liquid level. The degree of airflow disturbance.

[0081] The above method can be used to determine the degree of airflow disturbance at different liquid levels.

[0082] Step S300: Based on the distribution of airflow interference and steam concentration data at different liquid levels, determine the steam diffusion rate at different liquid levels.

[0083] The above steps calculated the airflow disturbances generated by the liquid at different liquid levels in the cryogenic storage tank. Airflow disturbances in the gas phase space affect the liquid's evaporation rate, primarily in two aspects: ① As airflow disturbance increases, the random movement of different gas molecules in the gas phase space increases, leading to a greater driving force for evaporation at the liquid surface and thus increasing the evaporation rate. ② Greater airflow disturbance can disrupt the gas film on the liquid surface, making the exchange interface between the liquid and air more active, thereby promoting evaporation.

[0084] Therefore, the air flow interference degree and the distribution of the vapor concentration data at different liquid levels are analyzed to determine the vapor diffusion rate at different liquid levels, which represents the influence of air flow interference on the liquid evaporation driving force. That is, in the gas phase space, the air flow disturbance promotes the evaporation diffusion by pushing the gas molecules to make the vapor molecules diffuse rapidly; meanwhile, the smaller the vapor concentration corresponding to the gas phase space below the liquid surface, the greater the diffusion power of the liquid surface vapor, and the greater the vapor diffusion rate.

[0085] In the embodiment of the present application, the vapor diffusion rate at different liquid levels is determined in step S300, including:

[0086] Firstly, the relative vapor concentration at different liquid levels is determined based on the difference between the vapor concentration data at different liquid levels and the vapor concentration in the initial full tank state. Specifically, for the current liquid level , the average value of the vapor concentration data at this liquid level is calculated to obtain the average vapor concentration, denoted as . The vapor concentration in the initial full tank state is obtained. Then, the difference between the average vapor concentration and the vapor concentration is calculated, and the difference is taken as the relative vapor concentration at the liquid level .

[0087] Secondly, the vapor diffusion rate at different liquid levels is determined based on the air flow interference degree and the relative vapor concentration at different liquid levels. Specifically, for the current liquid level , the ratio of the normalized value of the air flow interference degree and the relative vapor concentration is calculated, and the ratio is taken as the vapor diffusion rate at the liquid level , denoted as . Wherein, the smaller the value of the relative vapor concentration , the slower the vapor concentration rises with the decrease of the liquid level, and the weaker the diffusion power, so that the corresponding vapor diffusion rate is greater in combination with the air flow interference degree .

[0088] By the above method, the vapor diffusion rate at different liquid levels can be determined.

[0089] Step S400: Based on the vapor diffusion rate and in combination with the change of the liquid level data at different liquid levels, the influence factor of air flow disturbance on the evaporation rate at different liquid levels is determined.

[0090] Airflow disturbances affect not only the gas phase space but also the liquid phase space. Airflow disturbances cause fluctuations in the liquid surface; increased surface fluctuations typically increase the contact area between the liquid and the airflow, potentially promoting evaporation. Therefore, based on vapor diffusivity, it is necessary to analyze the impact of airflow disturbances on the liquid phase space by considering changes in liquid level data at different liquid heights, ultimately determining the influencing factors of airflow disturbances on the evaporation rate.

[0091] In this embodiment of the invention, step S400, determining the influence factor of airflow disturbance on the evaporation rate at different liquid level heights, includes:

[0092] Step S401: Based on the differences in liquid level monitoring data at different sampling points under different liquid levels, determine the degree of liquid level fluctuation under different liquid levels.

[0093] The degree of liquid surface fluctuation reflects the extent of liquid surface height variation at different locations under each liquid level. A greater degree of fluctuation at a given liquid level indicates more severe interference from airflow on the liquid surface, more frequent contact between the liquid and airflow, and consequently, a higher evaporation rate of the liquid in the tank. Therefore, the differences in liquid level monitoring data from different sampling points at different liquid levels are analyzed to determine the degree of liquid surface fluctuation at different liquid levels.

[0094] In this embodiment of the invention, step S400, determining the degree of liquid level fluctuation at different liquid level heights, includes:

[0095] First, in the liquid level monitoring data from all different sampling locations at different liquid level heights, the maximum and minimum height values, as well as the height difference between any two sampling locations at the same time, are determined. Specifically, for the current liquid level height... The maximum and minimum values ​​of the liquid level monitoring data from all different sampling locations were determined, thus obtaining the maximum and minimum height values, which were denoted as follows: and At the same time, at all different sampling locations From the liquid level monitoring data, determine any two sampling locations at the same time. Liquid level monitoring value and absolute value of the difference and the absolute value of the difference As a value of high difference.

[0096] Secondly, based on the distribution level of height difference values ​​corresponding to all sampling points at all times, the degree of fluctuation in liquid level height is determined. Specifically, for the current liquid level height... , determine the average value of the height difference values corresponding to all arbitrary two sampling positions at the same time, obtain the first height difference value, calculate the average value of the first height difference values at all times, obtain the second height difference value, take the second height difference value as the liquid level fluctuation degree, and mark it as . The liquid level fluctuation degree represents the non-uniformity of the liquid level fluctuation, and the greater the value, the more non-uniform the liquid level fluctuation, and the greater the fluctuation degree.

[0097] Finally, based on the maximum height value and the minimum height value under different liquid levels, and the liquid level fluctuation degree, the liquid level fluctuation degree under different liquid levels is determined. Specifically, for the current liquid level , the ratio of the maximum height value and the minimum height value is calculated. The ratio represents the amplitude range of the liquid level fluctuation at this height, and the greater the value, the more intense the fluctuation amplitude of the liquid level. Further, the product of the ratio and the liquid level fluctuation degree is calculated, and the product is taken as the liquid level fluctuation degree under the current liquid level , and is marked as .

[0098] In the above manner, the liquid level fluctuation degree under different liquid levels can be determined.

[0099] Step S402: Fusion of the vapor diffusion rate and the liquid level fluctuation degree to determine the influence factor of the airflow disturbance on the evaporation rate under different liquid levels.

[0100] The above-mentioned airflow interference under any liquid level in the low-temperature storage tank obtains the evaporation rate influence result of the gas phase space and the liquid phase space, that is, the vapor diffusion rate represents the influence degree of the airflow interference on the evaporation rate in the gas phase space, and the liquid level fluctuation degree represents the influence degree of the airflow interference on the evaporation rate in the liquid phase space. Therefore, by comprehensively considering the vapor diffusion rate and the liquid level fluctuation degree under different liquid levels, the influence factor of the airflow disturbance on the evaporation rate under different liquid levels can be determined.

[0101] In the embodiment of the present application, for the current liquid level , the product of the vapor diffusion rate and the liquid level fluctuation degree under this liquid level is calculated, and the product is taken as the influence factor of the airflow disturbance on the evaporation rate under this liquid level, and is marked as , at this time . Since the greater the vapor diffusion rate and the liquid level fluctuation degree, the greater the promotion degree of the evaporation rate, then The larger the value, the greater the influence of the corresponding liquid level height.

[0102] The above method can be used to determine the influence factor of airflow disturbance on evaporation rate at different liquid level heights.

[0103] Step S500: Based on the influence factor of the airflow disturbance on the evaporation rate, the initial estimated evaporation rate at different liquid level heights is corrected, and the corrected evaporation rate at different liquid level heights is determined.

[0104] Since the degree to which airflow disturbance promotes evaporation varies at different liquid levels, a larger influence factor indicates a greater degree of airflow disturbance at the corresponding liquid level, resulting in a larger deviation of the estimated evaporation rate from the actual evaporation rate and a greater degree of correction required, and vice versa. Therefore, by utilizing the influence factor of airflow disturbance on evaporation rate at different liquid levels, the initial estimated evaporation rate at different liquid levels is corrected, thus obtaining the corrected evaporation rate at different liquid levels.

[0105] In this embodiment of the invention, step S500, determining the corrected evaporation rate at different liquid level heights, includes:

[0106] First, the influencing factors are normalized to obtain the modified parameters. Specifically, for the current liquid level... The liquid level height is determined using a normalization function. Factors affecting evaporation rate Normalize to the range [0,1] to obtain the liquid level height. Modify the parameters below and record them as follows. .

[0107] Next, the sum of the modified parameter and the set value is determined to obtain the evaporation rate correction coefficient.

[0108] Finally, the product of the evaporation rate correction coefficient and the initial estimated evaporation rate at different liquid level heights is determined to obtain the corrected evaporation rate at different liquid level heights. Specifically, for the current liquid level height... Corrected evaporation rate ;in, Indicates liquid level height The initial estimated evaporation rate is as follows. This indicates the set value. This represents the evaporation rate correction factor. When the liquid level is... Modify parameters below The larger the value, the greater the degree to which airflow disturbance at the corresponding liquid level promotes the evaporation rate. Therefore, the greater the actual evaporation rate after weighting with this value as the weight.

[0109] By means, the estimated evaporation rate at different liquid levels can be corrected to obtain more accurate corrected evaporation rates at different liquid levels.

[0110] In the embodiments of the present application, the method further comprises: predicting the abnormal leakage of the low-temperature storage tank based on the corrected evaporation rate. Specifically, the occurrence of abnormal leakage is closely related to the evaporation behavior of the storage tank. Generally, the evaporation rate of the low-temperature storage tank will fluctuate within a certain range, and if the evaporation rate significantly exceeds the normal range, it may mean leakage or other faults. Therefore, by monitoring the evaporation rate, air pressure, temperature and other parameters of the storage tank in real time, using historical data and machine learning algorithms to establish a prediction model and set an alarm threshold, it helps relevant personnel to diagnose and repair faults. At the same time, regular equipment inspection, especially the state of valves, pipelines, seals and other components, ensures that there is no aging or damage to avoid causing leakage.

[0111] Based on the same inventive concept, the embodiments of the present application also provide a kind of evaporation rate dynamic monitoring device for static low-temperature storage tank, as shown in Figure 2 The device comprises:

[0112] The monitoring data acquisition module is configured to acquire monitoring data at different liquid levels inside the low-temperature storage tank, wherein the monitoring data includes vapor concentration data, airflow velocity data at different sampling positions, air pressure data and liquid level monitoring data;

[0113] The airflow disturbance degree analysis module is configured to analyze the changes of the airflow velocity data and the air pressure data at different sampling positions at different liquid levels, and determine the airflow disturbance degree at different liquid levels;

[0114] The vapor diffusion rate analysis module is configured to determine the vapor diffusion rate at different liquid levels based on the airflow disturbance degree at different liquid levels and the distribution of the vapor concentration data;

[0115] The influence factor analysis module is configured to determine the influence factor of the airflow disturbance on the evaporation rate at different liquid levels based on the vapor diffusion rate and the changes of the liquid level data at different liquid levels;

[0116] The evaporation rate correction module is configured to correct the initial estimated evaporation rate at different liquid levels based on the influence factor of the airflow disturbance on the evaporation rate, to obtain the corrected evaporation rate at different liquid levels.

[0117] It should be noted that: the device provided by the above embodiments is only exemplified by the division of the above functional modules, and in actual application, the above functions can be completed by different functional modules according to needs, i.e. the internal structure of the computer device is divided into different functional modules to complete all or part of the functions described above.

[0118] Based on the same inventive concept, the embodiment of the present application also provides a dynamic monitoring system for evaporation rate of static low-temperature storage tank, as shown in the figure, the system comprises: a memory 301, a processor 302, and computer program code 303 stored in the memory 301 and running on the processor 302, wherein the processor 302 executes the computer program code 303, so that the system can execute any one of the dynamic monitoring methods for evaporation rate of static low-temperature storage tank introduced above. Figure 3

[0119] The embodiment of the present application can divide the function modules of the system according to the above-mentioned method examples, for example, it can correspond to each function module, or two or more functions can be integrated in one processing module, and the integrated module can be realized in the form of hardware. It should be noted that the division of modules in the embodiment is illustrative, and is only a logical function division, and another division mode can be used in actual implementation.

[0120] Based on the same inventive concept, the embodiment of the present application also provides a computer program product, which comprises: computer program code, when the computer program code runs on a computer, so that the computer executes any one of the dynamic monitoring methods for evaporation rate of static low-temperature storage tank introduced above.

[0121] Based on the same inventive concept, the embodiment of the present application also provides a computer readable storage medium, which stores computer program code, when the computer program code runs on a computer, so that the computer executes any one of the dynamic monitoring methods for evaporation rate of static low-temperature storage tank introduced above.

[0122] It should be noted that: the above-mentioned embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.​

Claims

1. A method for dynamic monitoring of evaporation rate in stationary cryogenic storage tanks, characterized in that, Includes the following steps: Acquire monitoring data at different liquid levels inside the cryogenic storage tank. The monitoring data includes vapor concentration data, as well as airflow velocity data, air pressure data, and liquid level monitoring data at different sampling locations. Analyze the changes in airflow velocity and air pressure data at different sampling locations under different liquid levels to determine the airflow interference at different liquid levels. Based on the distribution of airflow interference and vapor concentration data at different liquid levels, the vapor diffusion rate at different liquid levels was determined. Based on the vapor diffusivity and combined with the changes in liquid level data at different liquid levels, the influence factor of airflow disturbance on evaporation rate at different liquid levels is determined. Based on the influence factor of the airflow disturbance on the evaporation rate, the initial estimated evaporation rate at different liquid level heights is corrected to obtain the corrected evaporation rate at different liquid level heights.

2. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 1, characterized in that, Determine the airflow disturbance at different liquid levels, including: Based on the difference distribution of airflow velocity data at different sampling locations under different liquid levels, the airflow velocity non-uniformity under different liquid levels is determined. Based on the difference between air pressure data at different sampling locations under different liquid levels, the degree of air pressure difference under different liquid levels is determined. By combining the airflow velocity non-uniformity and air pressure difference, the airflow interference degree at different liquid level heights is determined.

3. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 2, characterized in that, Determine the non-uniformity of airflow velocity at different liquid levels, including: Based on the distribution level of airflow velocity at different sampling locations under different liquid levels, the mean airflow velocity at each sampling location is determined. The airflow velocity difference at each time moment is determined based on the difference between the airflow velocity at different sampling locations and the mean airflow velocity. Based on the differences in airflow velocity at different times under different liquid levels, the non-uniformity of airflow velocity at different liquid levels is determined.

4. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 2, characterized in that, Determine the pressure difference at different liquid levels, including: Determine the pressure range corresponding to the pressure at different sampling locations at different liquid levels for each moment; Based on the distribution level of the pressure difference at different times under different liquid levels, the pressure difference degree under different liquid levels is determined.

5. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 1, characterized in that, Determining the vapor diffusivity at different liquid level heights includes: Based on the difference between the vapor concentration data at different liquid levels and the vapor concentration at the initial full tank state, the relative vapor concentration at different liquid levels is determined. Based on the airflow disturbance and relative vapor concentration at different liquid levels, the vapor diffusion rate at different liquid levels was determined.

6. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 1, characterized in that, The factors influencing the evaporation rate at different liquid level heights were determined, including: Based on the differences in liquid level monitoring data at different sampling points under different liquid levels, the degree of liquid level fluctuation under different liquid levels is determined. By combining the vapor diffusivity and the degree of liquid surface fluctuation, the influence factor of airflow disturbance on evaporation rate at different liquid surface heights is determined.

7. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 6, characterized in that, Determine the degree of liquid level fluctuation at different liquid level heights, including: In the liquid level monitoring data of all different sampling locations at different liquid level heights, determine the maximum height value and the minimum height value, as well as the height difference value of the liquid level monitoring values ​​of any two sampling locations at the same time. The degree of liquid level fluctuation is determined based on the distribution level of height difference values ​​corresponding to all sampling points at all times. Based on the maximum and minimum height values ​​at different liquid levels, and the degree of liquid level fluctuation, the degree of liquid level fluctuation at different liquid levels is determined.

8. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 1, characterized in that, The initial estimated evaporation rate at different liquid level heights is corrected based on the aforementioned influencing factors, including: The influencing factors are normalized to obtain the modified parameters; The sum of the modified parameter and the set value is determined to obtain the evaporation rate correction coefficient; The product of the evaporation rate correction coefficient and the initial estimated evaporation rate at different liquid level heights is determined to obtain the corrected evaporation rate at different liquid level heights.

9. The method for dynamic monitoring of evaporation rate in static cryogenic storage tanks according to claim 1, characterized in that, The method also includes: predicting abnormal leaks in cryogenic storage tanks based on the corrected evaporation rate.

10. A dynamic monitoring system for the evaporation rate of stationary cryogenic storage tanks, characterized in that, The system includes a memory, a processor, and executable computer program code stored in the memory and executable on the processor. When the processor executes the computer program code, it performs the dynamic monitoring method for evaporation rate of a stationary cryogenic storage tank as described in any one of claims 1 to 9.

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