Modeling method, calculation method, equipment, storage medium and product

Abstract

The invention discloses a modeling method, a calculation method, equipment, a storage medium and a product. The modeling method comprises the following steps: dividing a gas storage tank into a liquid phase region, a gas phase region, a liquid phase side wall surface and a gas phase side wall surface according to the form of carbon dioxide in the gas storage tank; according to the principles of mass conservation and energy conservation, carbon dioxide mathematical models of the liquid phase region, the gas phase region, the liquid phase side wall surface and the gas phase side wall surface are constructed respectively. The carbon dioxide mathematical model constructed according to the invention can well predict the change of the carbon dioxide supply parameters in the self-pressurization supply process, has good prediction precision, and avoids the problem that the coefficient k needs to be calibrated through tests for different test devices and different supply media.

Description

Technical Field

[0001] The present invention belongs to the technical field of modeling and simulation, and in particular relates to a carbon dioxide self-pressurization supply modeling method, calculation method, equipment, storage medium and product. Background Art

[0002] Carbon dioxide is stable, low-cost, non-toxic and pollution-free. It is used as a cooling medium to cool high-temperature components and plays a vital role in the thermal protection of high-temperature components. The physical parameters such as carbon dioxide supply pressure and temperature are affected by the carbon dioxide supply system. In order to predict the performance of the supply system, the supply process needs to be accurately modeled.

[0003] According to the different driving modes, the carbon dioxide supply system can be divided into pump-type and extrusion type. The pump-type carbon dioxide supply system relies on a pump to push the carbon dioxide flow, and requires power during operation, which increases the complexity of the system. According to whether the supply pressure is constant, the extrusion type carbon dioxide supply system can be divided into a high-pressure gas extrusion supply system and a self-pressurized supply system. The high-pressure gas extrusion supply system squeezes carbon dioxide through high-pressure gas to maintain a constant carbon dioxide pressure, but a high-pressure gas cylinder is required, which increases the system cost and weight. In the self-pressurized supply system, the pressure of carbon dioxide will gradually decrease. Once the pressure is lower than the saturated vapor pressure, part of the liquid will vaporize, and the resulting vapor will compensate for the carbon dioxide pressure, keeping its pressure relatively stable. The self-pressurized supply system has a simple and reliable structure, but the physical parameters of carbon dioxide will change during the supply process. Therefore, in order to master the performance of the self-pressurized supply system, it is necessary to accurately model the self-pressurized supply system.

[0004] The most widely used self-pressurized supply model is the model established by Zilliac and Karabeyoglu (hereinafter referred to as the ZK model). The ZK model divides carbon dioxide into three regions: liquid phase, gas phase and saturated thin layer. The heat and mass transfer process between the liquid phase and the gas phase is carried out through the thin layer, and it is assumed that the steam mass is equal to the ratio of the net absorption heat of the thin layer to the latent heat of carbon dioxide vaporization. In order to make the calculated value of the ZK model consistent with the experimental results, the gas generation mass needs to be multiplied by the coefficient k. For different test devices and different supply media, the coefficient k needs to be calibrated experimentally.

[0005] Zimmerman et al. conducted a self-pressurized supply experiment and found that phase change not only occurs at the gas-liquid surface, but also that the liquid will boil strongly inside during the self-pressurized supply process. Zilliac et al.'s assumptions about vapor quality are inconsistent with Zimmerman's experimental phenomena. For a self-pressurized supply system, the mass transfer rate from the liquid phase to the vapor phase must be correctly simulated to obtain a reasonable supply pressure prediction, so it is necessary to establish a new model to characterize vapor quality. Summary of the invention

[0006] The purpose of the present invention is to provide a modeling method, a calculation method, a device, a storage medium and a product to solve the problem that in the traditional ZK model, for different test devices and different supply media, the coefficient k needs to be obtained through experimental calibration, and the calibration process is complicated, which leads to complex ZK model calculation.

[0007] The present invention solves the above technical problems through the following technical solutions: a carbon dioxide self-pressurization supply modeling method, the modeling method comprising: According to the form of carbon dioxide in the gas tank, the gas tank is divided into a liquid phase area, a gas phase area, a liquid phase side wall surface and a gas phase side wall surface; According to the principles of conservation of mass and energy, mathematical models of carbon dioxide in the liquid phase region, gas phase region, liquid phase side wall surface and gas phase side wall surface are constructed respectively; wherein the mathematical model of carbon dioxide in the liquid phase region is: ; , ; , ; , ; Among them, m l , l 、u l , P l and V l They represent the mass, density, specific internal energy, pressure and volume of liquid carbon dioxide, t represents the supply time, dt represents the supply time increment, d(m l u l ) represents the internal energy increment of liquid carbon dioxide in the supply time increment dt, m vap Indicates the steam mass flow rate, m outlet represents the supply mass flow rate, h l represents the specific enthalpy of liquid carbon dioxide, h' g represents the specific enthalpy of saturated gas, Q wl It represents the heat flow between the liquid side wall and the liquid phase area, Q lg Represents the heat flow between the gas phase and the liquid phase, P g 、V g Respectively represent the pressure and volume of gaseous carbon dioxide, dV g represents the volume increment of gaseous carbon dioxide in the supply time increment dt, f( ) represents the Span-Wagner state equation, x represents the carbon dioxide dryness, A wl represents the contact area between the liquid phase side wall and liquid carbon dioxide, b wl represents the heat transfer coefficient between the liquid phase side wall and liquid carbon dioxide, Twl represents the liquid side wall temperature, T l represents the liquid phase temperature, A gl represents the contact area between gaseous carbon dioxide and liquid carbon dioxide, b gl represents the heat transfer coefficient between gaseous carbon dioxide and liquid carbon dioxide, T g represents the temperature of the gas phase; The mathematical model of carbon dioxide in the gas phase is: ; , , ; Among them, m g , g and u g denote the mass, density and specific internal energy of gaseous carbon dioxide, d(m g u g ) represents the internal energy increment of gaseous carbon dioxide in the supply time increment dt, Q wg A represents the heat flow between the gas phase side wall and the gas phase region, wg represents the contact area between the gas phase side wall and gaseous carbon dioxide, b wg represents the heat transfer coefficient between the gas phase side wall and gaseous carbon dioxide, T wg represents the gas phase side wall temperature; The mathematical model of carbon dioxide on the liquid phase side wall is: ; Among them, m sl represents the mass of the liquid side wall, c p represents the specific heat capacity of the solid wall, dT wl represents the temperature increment of the liquid side wall within the supply time increment dt; The mathematical model of carbon dioxide on the gas phase side wall is: ; Among them, m sg represents the mass of the gas phase side wall, dT wg It represents the temperature increment of the gas phase side wall within the supply time increment dt.

[0008] Furthermore, the steam mass flow rate m vap The calculation formula is: ; Where dt represents the supply time increment.

[0009] Furthermore, the heat transfer coefficient b between the liquid phase side wall and liquid carbon dioxide is solved according to the natural convection formula: wl, heat transfer coefficient b between gaseous carbon dioxide and liquid carbon dioxide gl , heat transfer coefficient b between gas phase side wall and gaseous carbon dioxide wg .

[0010] Based on the same concept, the present invention provides a method for calculating carbon dioxide self-pressurization supply parameters, comprising: Step S1: Obtain the pressure P of the liquid carbon dioxide when the carbon dioxide in the gas tank is fully liquid l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p ; Step S2: According to the pressure P of liquid carbon dioxide l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p Calculate the liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l ; Step S3: Calculate the pressure P of the liquid carbon dioxide according to the mathematical model of the carbon dioxide in the liquid phase region and the liquid phase side wall when the carbon dioxide in the gas tank is fully liquid l , liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l , carbon dioxide dryness x and the heat flow Q between the liquid side wall and the liquid region wl ; Step S4: Determine whether the carbon dioxide dryness x is greater than 0 and less than 1. If not, the supply time t is increased and the process goes to step S3; if yes, the process goes to step S5; Step S5: Calculate the heat flow Q between the liquid phase side wall and the liquid phase region according to the carbon dioxide mathematical model of the liquid phase region, gas phase region, liquid phase side wall and gas phase side wall in the carbon dioxide self-pressurization supply modeling method as described above. wl , heat flux Q between the gas phase side wall and the gas phase region wg , heat flow Q between gas phase and liquid phase lg , liquid side wall temperature T wl, gas phase side wall temperature T wg ; Step S6: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l 、Mass m l and volume V l , liquid phase temperature T l , Steam mass flow rate m vap , specific enthalpy of saturated gas h' g , carbon dioxide dryness x, mass of gaseous carbon dioxide m g , density ρ g , specific internal energy g 、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g ; Step S7: Determine the pressure P of gaseous carbon dioxide g Is it less than or equal to the pressure P of liquid carbon dioxide? l If not, then the volume of gaseous carbon dioxide V g Increase, and go to step S8; if yes, update the mass m of liquid carbon dioxide l , and proceed to step S9; Step S8: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l and volume V l , liquid phase temperature T l , density ρ g , specific internal energy g 、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g , and proceed to step S7; Step S9: Determine the mass m of liquid carbon dioxide l Is it less than or equal to 0? If so, the calculation of the carbon dioxide self-pressurization supply parameters is completed; if not, the supply time t is increased and the process goes to step S5.

[0011] Furthermore, in step S3, when the carbon dioxide in the gas storage tank is in a fully liquid state, the mathematical model of carbon dioxide in the liquid phase is: ; , , ; The mathematical model of carbon dioxide on the liquid phase side wall is: ; Where f( ) represents the Span-Wagner state equation, dt represents the supply time increment, d(m l u l ) represents the internal energy increment of liquid carbon dioxide in the supply time increment dt, dT wl It represents the temperature increment of the liquid side wall within the supply time increment dt.

[0012] Furthermore, in step S8, the mass m of the liquid carbon dioxide is l The update formula is: ; Among them, m' l represents the updated mass of liquid carbon dioxide, m l Indicates the mass of liquid carbon dioxide before the update.

[0013] Based on the same concept, the present invention also provides an electronic device, including a memory, a processor, and a computer program / instructions stored on the memory, wherein the processor executes the computer program / instructions to implement the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method as described above.

[0014] Based on the same concept, the present invention also provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method as described above.

[0015] Based on the same concept, the present invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method as described above.

[0016] Compared with the prior art, the advantages of the present invention are: The present invention provides a carbon dioxide self-pressurizing supply modeling method. For different test devices and different supply media, there is no need to calibrate the coefficient k through experiments, thereby avoiding the calibration of the coefficient k and simplifying the calculation of the carbon dioxide self-pressurizing supply parameters. At the same time, the carbon dioxide mathematical model constructed according to the present invention can well predict the changes in the carbon dioxide supply parameters during the self-pressurizing supply process, indicating that the carbon dioxide mathematical model constructed according to the present invention has good prediction accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 Schematic diagram of the division of gas storage tanks in an embodiment of the present invention; Figure 2 is a schematic diagram of energy and mass transfer between different zones in an embodiment of the present invention; Figure 3 is a schematic diagram of mass transfer between liquid carbon dioxide and gaseous carbon dioxide in an embodiment of the present invention; Figure 4 This is a schematic diagram of a carbon dioxide self-pressurization supply test system according to an embodiment of the present invention; Figure 5 is a comparison chart of the test results of test condition 1 in the embodiment of the present invention and the simulation results obtained by using the carbon dioxide mathematical model constructed by the present invention; Figure 6 is a comparison chart of the test results of test condition 2 in the embodiment of the present invention and the simulation results obtained by using the carbon dioxide mathematical model constructed by the present invention; Figure 7 is a comparison chart of the test results of test condition 3 in the embodiment of the present invention and the simulation results obtained by using the carbon dioxide mathematical model constructed by the present invention; Figure 8 is a flow chart of the method for calculating the parameters of the self-pressurized carbon dioxide supply in the embodiment of the present invention, wherein t' represents the updated supply time, V' g Represents the updated volume of gaseous carbon dioxide. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The technical solution of the present application is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0021] Example 1 A carbon dioxide self-pressurization supply modeling method provided in an embodiment of the present invention comprises the following steps: Step A1: dividing the gas storage tank into a liquid phase region, a gas phase region, a liquid phase side wall surface and a gas phase side wall surface according to the form of carbon dioxide in the gas storage tank; Step A2: According to the principles of conservation of mass and energy, mathematical models of carbon dioxide are constructed for the liquid phase region, gas phase region, liquid phase side wall surface and gas phase side wall surface respectively.

[0022] like Figure 1 As shown, the carbon dioxide storage tank is divided into a liquid phase area, a gas phase area, a liquid phase side wall surface and a gas phase side wall surface, and each area is an independent control body. The present invention takes into account the influence of side wall heat transfer on carbon dioxide pressure, making the constructed carbon dioxide mathematical model more accurate.

[0023] For ease of calculation, it is assumed that the carbon dioxide fluid is evenly distributed and the temperature of each point in the gas phase or liquid phase is the same; only the heat transfer between different phases is considered, and the heat transfer within the phase is not considered. In addition, all heat transfer calculations in the gas tank are based on the natural convection mechanism.

[0024] At the same time, the outer layer of the gas tank is wrapped with insulation material, so the heat exchange between the gas tank and the environment is not considered in the modeling process. In addition, the flow rate of supplied carbon dioxide is low, so the pressure of liquid carbon dioxide in the gas tank can be considered to be the same as that of gaseous carbon dioxide.

[0025] Figure 2 shows the energy and mass transfer process between different zones, m vap Indicates the steam mass flow rate, m outlet represents the supply mass flow rate, Q wl It represents the heat flow between the liquid side wall and the liquid phase area, Q lg It represents the heat flow between the gas phase and the liquid phase, Q wg represents the heat flow between the gas phase side wall and the gas phase region, T wl represents the liquid side wall temperature, T l represents the liquid phase temperature, T wg represents the gas phase side wall temperature, T g represents the gas phase temperature, H g , H l They represent the gas phase side wall height (or gas phase region height) and the liquid phase side wall height (or liquid phase region height), respectively. The subscript g represents gas, and the subscript l represents liquid. According to the principles of mass conservation and energy conservation, the mass and energy conservation equations of carbon dioxide in the liquid phase can be obtained (such as formula (1) and formula (2)), that is, the mathematical model of carbon dioxide in the liquid phase is obtained: (1) (2) (3) (4) (5) (6) (7) (8) Among them, m l , l 、u l , P l and V l They represent the mass, density, specific internal energy, pressure and volume of liquid carbon dioxide, t represents the supply time, dt represents the supply time increment, d(m l u l ) represents the internal energy increment of liquid carbon dioxide in the supply time increment dt, h l represents the specific enthalpy of liquid carbon dioxide, h' g represents the specific enthalpy of saturated gas, P g 、V g Respectively represent the pressure and volume of gaseous carbon dioxide, dV g represents the volume increment of gaseous carbon dioxide in the supply time increment dt, f( ) represents the Span-Wagner state equation, x represents the carbon dioxide dryness, A wl represents the contact area between the liquid phase side wall and liquid carbon dioxide, b wl A represents the heat transfer coefficient between the liquid phase side wall and liquid carbon dioxide, gl represents the contact area between gaseous carbon dioxide and liquid carbon dioxide, b gl It represents the heat transfer coefficient between gaseous carbon dioxide and liquid carbon dioxide.

[0026] Figure 3 The mass transfer process between liquid carbon dioxide and gaseous carbon dioxide is shown. During the supply process, as the pressure of carbon dioxide continues to drop, the liquid carbon dioxide will boil due to the pressure reduction and produce saturated vapor; due to the low density of saturated vapor, it will float up into the gas phase. Assuming that when the liquid carbon dioxide boils, the saturated vapor will quickly enter the gas phase, and the entire mass of saturated vapor will enter the gas phase in the time period t to t+dt. In a specific embodiment of the present invention, the mass m of the liquid carbon dioxide at the supply time t is used. l The product of the carbon dioxide dryness x is used to characterize the steam mass entering the gas phase at t~t+dt, that is, the steam mass flow rate m vap The calculation formula is: (9) Here, dt represents the increment of supply time.

[0027] At the initial moment (i.e., supply time t=0), the carbon dioxide in the gas tank is completely liquid, that is, there is no gas phase region and gas phase side wall surface. At this time, the mass conservation equation of liquid carbon dioxide is: (10) The energy conservation equation for liquid carbon dioxide is: (11) When the carbon dioxide in the gas tank is fully liquid, the volume of the liquid carbon dioxide is equal to the volume of the gas tank, so the specific enthalpy of the liquid carbon dioxide is h l It can be solved by formula (12) and formula (13): (12) (13) For the liquid phase side wall, the mathematical model of carbon dioxide is: (14) (15) Among them, m sl represents the mass of the liquid side wall, c p represents the specific heat capacity of the solid wall (i.e. the specific heat capacity of the gas tank), dT wl It represents the temperature increment of the liquid side wall within the supply time increment dt, and D represents the inner diameter of the gas storage tank.

[0028] At the initial moment (i.e., supply time t=0), the carbon dioxide in the gas tank is in a completely liquid state, that is, there is no gas phase region and gas phase side wall surface, and the energy conservation equation of the liquid phase side wall surface is: (16) Among them, m s Indicates the quality of the gas tank.

[0029] The carbon dioxide dryness can be calculated using formula (5), and then whether carbon dioxide vapor is generated can be determined based on the carbon dioxide dryness. When 0<x<1, it indicates that the carbon dioxide is in a saturated state, carbon dioxide vapor is generated, and the supercooled liquid supply stage ends.

[0030] According to the principles of conservation of mass and energy, the mass and energy conservation equations of carbon dioxide in the gas phase can be obtained (such as formula (17) and formula (18)), that is, the mathematical model of carbon dioxide in the gas phase is obtained: (17) (18) (19) (20) (twenty one) Among them, m g , g and u g denote the mass, density and specific internal energy of gaseous carbon dioxide, d(m g u g ) represents the internal energy increment of gaseous carbon dioxide in the supply time increment dt, Q wg A represents the heat flow between the gas phase side wall and the gas phase region, wg represents the contact area between the gas phase side wall and gaseous carbon dioxide, b wg represents the heat transfer coefficient between the gas phase side wall and gaseous carbon dioxide, T wg represents the gas phase side wall temperature.

[0031] The heat transfer process in the supply system satisfies the natural convection mechanism, so the natural convection formula is used to solve the heat transfer coefficient b between the liquid side wall and liquid carbon dioxide. wl , heat transfer coefficient b between gaseous carbon dioxide and liquid carbon dioxide gl , heat transfer coefficient b between gas phase side wall and gaseous carbon dioxide wg .

[0032] For the gas phase side wall, the mathematical model of carbon dioxide is: (twenty two) (twenty three) Among them, m sg represents the mass of the gas phase side wall, dT wg represents the temperature increment of the gas phase side wall within the supply time increment dt, H represents the height of the gas storage tank, H g Indicates the gas phase side wall or the height of the gas phase region.

[0033] In order to achieve a higher heat exchange effect between carbon dioxide and high-temperature components, the phase of the supplied carbon dioxide must be liquid. Therefore, the present invention is aimed at the supply process of liquid carbon dioxide. When the carbon dioxide in the gas tank is all in gaseous state, the calculation is terminated.

[0034] In order to verify the accuracy and reliability of the model of the present invention, a Figure 4 The carbon dioxide self-pressurization supply test system shown in the figure mainly includes multiple control valves (such as the inflation valve G1, the solenoid valve G2 and the deflation valve G3), an orifice plate and a carbon dioxide gas storage tank. The inflation valve G1, the solenoid valve G2 and the deflation valve G3 are used to control the filling, supply and exhaust of carbon dioxide respectively, and the orifice plate is used to control the supply flow of carbon dioxide. The carbon dioxide gas storage tank is made of a titanium alloy lining and a composite material woven for storing carbon dioxide.

[0035] The system also includes a pressure sensor P1 / P2, a mass flow meter F and an electronic scale. The pressure sensor P1 / P2 is used to measure the carbon dioxide supply pressure P, and the mass flow meter is used to measure the mass flow rate m of the supplied carbon dioxide. outlet , an electronic scale is used to measure the weight of the filled carbon dioxide.

[0036] Three groups of carbon dioxide self-pressurization supply tests were carried out, and the test conditions are shown in Table 1.

[0037] Table 1 Carbon dioxide self-pressurization supply test conditions

[0038] As the supply time increases, the test results under the three test conditions and the simulation results obtained by using the carbon dioxide mathematical model constructed by the present invention are as follows: Figures 5 to 7 As shown. Figures 5 to 7 It can be seen that the simulation results of the present invention have good supply pressure prediction accuracy, indicating that the carbon dioxide mathematical model constructed by the present invention can well predict the change of carbon dioxide supply pressure over time during the self-pressurized supply process.

[0039] Example 2 like Figure 8 As shown, a method for calculating carbon dioxide self-pressurization supply parameters provided by an embodiment of the present invention includes the following steps: Step S1: Obtain the pressure P of the liquid carbon dioxide when the carbon dioxide in the gas tank is fully liquid l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p .

[0040] At the initial supply time, that is, supply time t=0, the carbon dioxide in the gas tank is fully liquid, and the pressure P of the liquid carbon dioxide can be measured experimentally. l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p .

[0041] Step S2: According to the pressure P of liquid carbon dioxide l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass ms and the specific heat capacity of the solid wall c p Calculate the liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l .

[0042] like Figure 1 As shown, the gas tank is divided into a gas phase region, a liquid phase region, a gas phase side wall surface and a liquid phase side wall surface according to the form of carbon dioxide in the gas tank. When the carbon dioxide in the gas tank is in a fully liquid state, there is no gas phase region and a gas phase side wall surface. At the initial moment (i.e., supply time t = 0), the carbon dioxide in the gas tank is in a fully liquid state, i.e., there is no gas phase region and a gas phase side wall surface. Therefore, the specific internal energy u of liquid carbon dioxide is calculated according to formula (11): l , calculate the density ρ of liquid carbon dioxide according to formula (12) l , calculate the specific enthalpy of liquid carbon dioxide h according to formula (13) l .

[0043] Liquid phase temperature T l and the liquid side wall temperature T wl The calculation is an existing technology, which can be found in the literature: Wang Zhengkai, Research on self-pressurization scheme based on regenerative cooling [D]. National University of Defense Technology, 2015.

[0044] Step S3: Calculate the pressure P of the liquid carbon dioxide according to the mathematical model of the carbon dioxide in the liquid phase region and the liquid phase side wall when the carbon dioxide in the gas tank is fully liquid l , liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l , carbon dioxide dryness x and the heat flow Q between the liquid side wall and the liquid region wl .

[0045] Whether carbon dioxide vapor is generated is determined based on the carbon dioxide dryness x. When the carbon dioxide dryness x≤0, it indicates that the carbon dioxide in the gas tank is fully liquid. When the carbon dioxide dryness x≥1, it indicates that the carbon dioxide in the gas tank is fully gaseous, and the calculation ends. When 0<carbon dioxide dryness x<1, it indicates that carbon dioxide vapor is generated, and the carbon dioxide in the gas tank is partially gaseous and partially liquid, and there is a gas phase area and a gas phase side wall.

[0046] The carbon dioxide dryness x is calculated according to formula (5), and the heat flow Q between the liquid phase side wall and the liquid phase region is calculated according to formula (7): wl, according to formula (3), calculate the pressure P of liquid carbon dioxide l , liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l The calculation of is the same as that in step S2.

[0047] Step S4: Determine whether the carbon dioxide dryness x is greater than 0 and less than 1. If not, the supply time t is increased (the increment is dt) and the process goes to step S3; if yes, the process goes to step S5.

[0048] When the carbon dioxide dryness x≤0, repeat step S3; when 0<carbon dioxide dryness x<1, it indicates that there are gas phase area and gas phase side wall surface, and go to step S5.

[0049] Step S5: Calculate the heat flow Q between the liquid phase side wall and the liquid phase region according to the carbon dioxide mathematical model of the liquid phase region, the gas phase region, the liquid phase side wall and the gas phase side wall in the carbon dioxide self-pressurization supply modeling method described in Example 1 wl , heat flux Q between the gas phase side wall and the gas phase region wg , heat flow Q between gas phase and liquid phase lg , liquid side wall temperature T wl , gas phase side wall temperature T wg .

[0050] According to formula (7), formula (21) and formula (8), the heat flux Q between the liquid side wall and the liquid region is calculated respectively: wl , heat flux Q between the gas phase side wall and the gas phase region wg , heat flow Q between gas phase and liquid phase lg , gas phase side wall temperature T wg The calculation is an existing technology, which can be found in the literature: Wang Zhengkai, Research on self-pressurization scheme based on regenerative cooling [D]. National University of Defense Technology, 2015.

[0051] Step S6: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l 、Mass m l and volume V l , liquid phase temperature T l , Steam mass flow rate m vap , specific enthalpy of saturated gas h' g , carbon dioxide dryness x, mass of gaseous carbon dioxide m g , density ρ g , specific internal energy g、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g .

[0052] The density of liquid carbon dioxide is l , specific internal energy l and pressure P l , liquid phase temperature T l The calculation of carbon dioxide dryness x is the same as that in step S3. The specific enthalpy h' of saturated gas is calculated according to formula (4): g .

[0053] The carbon dioxide dryness x is calculated according to formula (5), and then the steam mass flow rate m is obtained according to formula (9): vap As the steam enters the gas phase, P g Greater than P l , therefore, the gas phase will expand. Assume that the volume of gaseous carbon dioxide is V g The increment is dv, then the volume of liquid carbon dioxide in the liquid phase is updated to V' l =V l -dv; the volume of gaseous carbon dioxide in the gas phase is updated to V' g =V g +dv. Then, according to the geometric relationship, the height H of the liquid phase can be obtained. l The height H of the gas phase g .

[0054] The mass of carbon dioxide in the liquid phase is updated to m' l =m l -m vap ×dt; the mass of carbon dioxide in the gas phase is updated to m' g =m g +m vap ×dt; the carbon dioxide density in the liquid phase is ρ l =m' l / V' l ; The carbon dioxide density in the gas phase is ρ g =m' g / V' g ; u is calculated based on the energy conservation equation (2) in the liquid phase and the energy conservation equation (18) in the gas phase. l with u g .

[0055] According to the Span-Wagner state equation, the pressures P in the liquid phase and gas phase can be obtained respectively. l , P g Similarly, the temperature T of the liquid phase and the gas phase can be calculated respectively.l , T g .

[0056] Step S7: Determine the pressure P of gaseous carbon dioxide g Is it less than or equal to the pressure P of liquid carbon dioxide? l If not, then the volume of gaseous carbon dioxide V g Increase (increment dv), and go to step S8; if yes, update the mass m of liquid carbon dioxide l , and go to step S9.

[0057] In this embodiment, the mass of liquid carbon dioxide m l The update formula is: m' l =m l -m outlet ×dt (24) Among them, m' l represents the updated mass of liquid carbon dioxide, m l Indicates the mass of liquid carbon dioxide before the update.

[0058] Step S8: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l and volume V l , liquid phase temperature T l , density ρ g , specific internal energy g 、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g , and go to step S7.

[0059] Step S9: Determine the mass m of liquid carbon dioxide l Is it less than or equal to 0? If so, the calculation of the carbon dioxide self-pressurization supply parameters is completed; if not, the supply time t is increased (the increment is dt), and the process goes to step S5.

[0060] The carbon dioxide self-pressurization supply parameter calculation method of the present invention can be used to predict various parameters in the carbon dioxide self-pressurization supply process in real time until the carbon dioxide in the gas storage tank is completely in a gaseous state. The simulation results in Example 1 show that the carbon dioxide self-pressurization supply parameter calculation method of the present invention has good supply parameter prediction accuracy.

[0061] Example 3 An embodiment of the present invention also provides an electronic device, which includes: a memory, a processor and a computer program / instructions stored in the memory, and the processor executes the computer program / instructions to implement the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method in the embodiment of the present application.

[0062] Although not shown, the electronic device includes a processor that can perform various appropriate operations and processes according to the programs and / or data stored in the read-only memory (ROM) or the programs and / or data loaded from the storage part into the random access memory (RAM). The processor can be a multi-core processor or can include multiple processors. In some embodiments, the processor can include a general-purpose main processor and one or more special coprocessors, such as a central processing unit, a graphics processing unit (GPU), a neural network processor (NPU), a digital signal processor (DSP), etc. In RAM, various programs and data required for device operation are also stored. The processor, ROM, and RAM are connected to each other via a bus. The input / output (I / O) interface is also connected to the bus.

[0063] The processor and memory are used together to execute the program / instructions stored in the memory. When the program / instructions are executed by the computer, the methods, steps or functions described in the above embodiments can be implemented.

[0064] Although not shown, an embodiment of the present invention further provides a computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method in the embodiment of the present application.

[0065] Readable storage media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0066] Although not shown, an embodiment of the present invention further provides a computer program product, including: a computer program / instruction, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method or the carbon dioxide self-pressurization supply parameter calculation method in the embodiment of the present application.

[0067] What is disclosed above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or modifications within the technical scope disclosed in the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A carbon dioxide self-pressurization supply modeling method, characterized in that: The modeling method comprises: According to the form of carbon dioxide in the gas tank, the gas tank is divided into a liquid phase area, a gas phase area, a liquid phase side wall surface and a gas phase side wall surface; According to the principles of conservation of mass and energy, mathematical models of carbon dioxide in the liquid phase region, gas phase region, liquid phase side wall surface and gas phase side wall surface are constructed respectively; wherein the mathematical model of carbon dioxide in the liquid phase region is: ； ， ； ， ； ， ； Among them, m l , l 、u l , P l and V l They represent the mass, density, specific internal energy, pressure and volume of liquid carbon dioxide, t represents the supply time, dt represents the supply time increment, d(m l u l ) represents the internal energy increment of liquid carbon dioxide in the supply time increment dt, m vap Indicates the steam mass flow rate, m outlet represents the supply mass flow rate, h l represents the specific enthalpy of liquid carbon dioxide, h' g represents the specific enthalpy of saturated gas, Q wl It represents the heat flow between the liquid side wall and the liquid phase area, Q lg Represents the heat flow between the gas phase and the liquid phase, P g 、V g Respectively represent the pressure and volume of gaseous carbon dioxide, dV g represents the volume increment of gaseous carbon dioxide in the supply time increment dt, f( ) represents the Span-Wagner state equation, x represents the carbon dioxide dryness, A wl represents the contact area between the liquid phase side wall and liquid carbon dioxide, b wl represents the heat transfer coefficient between the liquid phase side wall and liquid carbon dioxide, T wl represents the liquid side wall temperature, T l represents the liquid phase temperature, A gl represents the contact area between gaseous carbon dioxide and liquid carbon dioxide, b gl represents the heat transfer coefficient between gaseous carbon dioxide and liquid carbon dioxide, T g represents the temperature of the gas phase; The mathematical model of carbon dioxide in the gas phase is: ； ， ， ； Among them, m g , g and u g denote the mass, density and specific internal energy of gaseous carbon dioxide, d(m g u g ) represents the internal energy increment of gaseous carbon dioxide in the supply time increment dt, Q wg A represents the heat flow between the gas phase side wall and the gas phase region, wg represents the contact area between the gas phase side wall and the gaseous carbon dioxide, b wg represents the heat transfer coefficient between the gas phase side wall and gaseous carbon dioxide, T wg represents the gas phase side wall temperature; The mathematical model of carbon dioxide on the liquid phase side wall is: ； Among them, m sl represents the mass of the liquid side wall, c p represents the specific heat capacity of the solid wall, dT wl represents the temperature increment of the liquid side wall within the supply time increment dt; The mathematical model of carbon dioxide on the gas phase side wall is: ； Among them, m sg represents the mass of the gas phase side wall, dT wg It represents the temperature increment of the gas phase side wall within the supply time increment dt.

2. The carbon dioxide self-pressurization supply modeling method according to claim 1, characterized in that: The steam mass flow rate m vap The calculation formula is: ； Where dt represents the supply time increment.

3. The carbon dioxide self-pressurization supply modeling method according to claim 1 or 2, characterized in that: According to the natural convection formula, the heat transfer coefficient b between the liquid side wall and liquid carbon dioxide is solved wl , heat transfer coefficient b between gaseous carbon dioxide and liquid carbon dioxide gl , heat transfer coefficient b between gas phase side wall and gaseous carbon dioxide wg .

4. A method for calculating carbon dioxide self-pressurization supply parameters, characterized in that: The calculation method includes: Step S1: Obtain the pressure P of the liquid carbon dioxide when the carbon dioxide in the gas tank is fully liquid l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p ; Step S2: According to the pressure P of liquid carbon dioxide l and mass m l , supply mass flow rate m outlet , gas tank volume V, gas tank height H, gas tank inner diameter D, gas tank mass m s and the specific heat capacity of the solid wall c p , calculate the liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l and specific enthalpy h l ; Step S3: Calculate the pressure P of the liquid carbon dioxide according to the mathematical model of the carbon dioxide in the liquid phase region and the liquid phase side wall when the carbon dioxide in the gas tank is fully liquid l , liquid phase temperature T l , liquid side wall temperature T wl , the density of liquid carbon dioxide ρ l , specific internal energy l , specific enthalpy h l , carbon dioxide dryness x and the heat flow Q between the liquid side wall and the liquid region wl ; Step S4: Determine whether the carbon dioxide dryness x is greater than 0 and less than 1. If not, the supply time t is increased and the process proceeds to step S3; if yes, the process proceeds to step S5; Step S5: Calculate the heat flow Q between the liquid phase side wall and the liquid phase region according to the carbon dioxide mathematical model of the liquid phase region, the gas phase region, the liquid phase side wall and the gas phase side wall in the carbon dioxide self-pressurization supply modeling method according to any one of claims 1 to 3 wl , heat flux Q between the gas phase side wall and the gas phase region wg , heat flow Q between gas phase and liquid phase lg , liquid side wall temperature T wl , gas phase side wall temperature T wg ; Step S6: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l 、Mass m l and volume V l , liquid phase temperature T l , Steam mass flow rate m vap , specific enthalpy of saturated gas h' g , carbon dioxide dryness x, mass of gaseous carbon dioxide m g , density ρ g , specific internal energy g 、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g ; Step S7: Determine the pressure P of gaseous carbon dioxide g Is it less than or equal to the pressure P of liquid carbon dioxide? l If not, then the volume of gaseous carbon dioxide V g Increase, and go to step S8; if yes, update the mass m of liquid carbon dioxide l , and proceed to step S9; Step S8: Calculate the density ρ of liquid carbon dioxide l , specific internal energy l 、Pressure P l and volume V l , liquid phase temperature T l , density ρ g , specific internal energy g 、Pressure P g and volume V g , gas phase temperature T g , Liquid phase height H l , gas phase height H g , and proceed to step S7; Step S9: Determine the mass m of liquid carbon dioxide l Is it less than or equal to 0? If so, the calculation of the carbon dioxide self-pressurization supply parameters is completed; if not, the supply time t is increased and the process goes to step S5.

5. The method for calculating the carbon dioxide self-pressurization supply parameters according to claim 4, characterized in that: In step S3, when the carbon dioxide in the gas storage tank is in a fully liquid state, the mathematical model of carbon dioxide in the liquid phase is: ； ， ， ； The mathematical model of carbon dioxide on the liquid phase side wall is: ； Where f( ) represents the Span-Wagner state equation, dt represents the supply time increment, d(m l u l ) represents the internal energy increment of liquid carbon dioxide in the supply time increment dt, dT wl It represents the temperature increment of the liquid side wall within the supply time increment dt.

6. The method for calculating the carbon dioxide self-pressurization supply parameters according to claim 4 or 5, characterized in that: In step S8, the mass m of the liquid carbon dioxide l The update formula is: ； Among them, m' l represents the updated mass of liquid carbon dioxide, m l Indicates the mass of liquid carbon dioxide before the update.

7. An electronic device comprising a memory, a processor, and a computer program / instruction stored in the memory, wherein the processor executes the computer program / instruction to implement the carbon dioxide self-pressurization supply modeling method as described in any one of claims 1 to 3 or the carbon dioxide self-pressurization supply parameter calculation method as described in any one of claims 4 to 6.

8. A computer-readable storage medium having a computer program / instruction stored thereon, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method as described in any one of claims 1 to 3 or the carbon dioxide self-pressurization supply parameter calculation method as described in any one of claims 4 to 6.

9. A computer program product, comprising a computer program / instruction, which, when executed by a processor, implements the carbon dioxide self-pressurization supply modeling method as described in any one of claims 1 to 3 or the carbon dioxide self-pressurization supply parameter calculation method as described in any one of claims 4 to 6.

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