Simulation calculation method and device for low-temperature rectification separation of helium isotope

Abstract

The invention provides a simulation calculation method and device for low-temperature rectification separation of helium isotopes, and the method comprises the steps: building a mathematical model of a helium isotope low-temperature rectification tower, and determining initial parameters which comprise a temperature initial value, a phase equilibrium constant initial value and a gas phase flow initial value; based on the initial parameters, solving a component material balance equation set and a phase balance equation set of each component by utilizing a tridiagonal matrix method to obtain the liquid-phase component concentration of each component on each tower plate; according to the liquid phase component concentration of each component on each tower plate, the temperature is corrected by utilizing the mole fraction sum equation set, the gas phase flow is corrected by utilizing the heat balance equation set, and finally the component concentration, temperature and gas-liquid phase flow of the helium isotope in the rectifying tower and the heat load of a tower top condenser and a tower bottom reboiler are simulated.

Description

Technical Field

[0001] The present invention relates to the technical field of cryogenic distillation, and in particular to a simulation calculation method and device for separating helium isotopes by cryogenic distillation. Background Art

[0002] Helium-3 and helium-4, as the main stable helium isotopes, often exist in the form of a mixture. The separation of helium-3 and helium-4, that is, the separation of helium isotopes, has important applications in the fields of medicine, nuclear industry, and aerospace industry. Since the 1950s, scientists have begun to study the separation methods of helium isotopes. Among them, the hot flushing and superleakage methods utilize the superfluidity of helium-4 at Tλ (2.17K) temperature, so the separation temperature must be reduced to below Tλ temperature; the hot flushing method is gradually eliminated due to its low separation efficiency; although the membrane separation method can avoid separation below the temperature of liquid helium, the membrane technology for helium isotope separation is not yet mature. As a mature and simple separation method, cryogenic distillation can achieve efficient separation of helium isotopes by utilizing the different boiling points of helium isotopes.

[0003] It is not difficult to find that there are very few research reports on cryogenic distillation of helium isotopes since the 21st century. In particular, due to the high cost and scarcity of helium-3, it is extremely difficult to carry out experiments on cryogenic distillation of helium isotopes, so cryogenic distillation simulation is particularly important. However, as the gas with the lowest boiling point, helium-4 has a boiling point of 4.2K and helium-3 has a boiling point of 3.19K. Its physical properties at low temperatures are difficult to be uniformly described by the equation of state, and vapor-liquid equilibrium data are particularly lacking. It is difficult to achieve distillation simulation of helium isotopes using commercial chemical process simulation software (Aspen Plus, Chemcad, etc.). Summary of the invention

[0004] The present invention provides a simulation calculation method and device for separating helium isotopes by cryogenic distillation, which are used to solve the defect that it is difficult to realize the distillation simulation of helium isotopes in the prior art.

[0005] The present invention provides a simulation calculation method for cryogenic distillation separation of helium isotopes, comprising:

[0006] A mathematical model of a helium isotope cryogenic distillation tower is established, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, the gas and liquid two-phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate is in a phase equilibrium state with the liquid mixture; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower comprises N tower plates and M components, and each tower plate serves as an equilibrium stage of the mathematical model; the mathematical model comprises a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium stages;

[0007] Determining initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate;

[0008] Based on the initial parameters, a tridiagonal matrix method is used to solve a component material balance equation group and a phase equilibrium equation group of each component to obtain a liquid phase component concentration of each component on each tray;

[0009] According to the liquid phase component concentration of each component on each tower plate, the temperature is corrected using the mole fraction addition equation group, and the gas phase flow rate is corrected using the heat balance equation group, and finally the component concentration, temperature, gas-liquid phase flow rate of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler are simulated.

[0010] According to a simulation calculation method provided by the present invention, determining initial parameters includes:

[0011] The initial value of each tray temperature is obtained by linear interpolation based on the bubble point temperature of the mixture generated on the tray at the top of the tower and the dew point temperature of the mixture generated on the tray at the bottom of the tower;

[0012] The initial value of the phase equilibrium constant is calculated based on the ideal K-model equation;

[0013] The initial value of the gas phase flow rate is determined according to the constant molar flow assumption and the heat balance equations, wherein the constant molar flow assumption is that the rising steam molar flows in the rectifying section and the stripping section are equal.

[0014] According to a simulation calculation method provided by the present invention, the initial value of the phase equilibrium constant is calculated according to the ideal K-model equation, including:

[0015]

[0016] in, is the saturated vapor pressure of component i, and p is the total pressure;

[0017] The components include helium-3 and helium-4. The saturated vapor pressure of helium-3 and helium-4 is calculated by the following formula:

[0018] The formula for the saturated vapor pressure of helium-4 is:

[0019]

[0020]

[0021]

[0022] The formula for the saturated vapor pressure of helium-3 is:

[0023]

[0024] Among them, p represents, p c Indicates that a k T stands for T c represents, θ represents, and b represents.

[0025] According to a simulation calculation method provided by the present invention, the component material balance equation group is implemented by the following formula:

[0026] L j-1 x i,j-1 +V j+1 y i,j+1 +F j z i,j -(L j +U j )x i,j -(V j +W j )y i,j =0

[0027] Among them, L j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; x i,j is the liquid component concentration of component i on the jth plate; y i,j is the gas phase component concentration of component i on the jth tower plate; F j is the feed flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j is the gas phase flow rate extracted from the side line on the jth tower plate;

[0028] The phase equilibrium equations are implemented by the following formula:

[0029] y i,j -K i,j x i,j =0

[0030] Among them, K i,jis the phase equilibrium constant of component i on the jth tower plate.

[0031] According to a simulation calculation method provided by the present invention, the temperature is corrected by using the mole fraction addition equation group according to the liquid phase component concentration of each component on each tray, including:

[0032] Substitute the solved concentration of the liquid phase components on each plate into the mole fraction addition equation group to determine whether the sum of the mole fractions of the liquid phase components on each plate is equal to 1;

[0033] If the sum of the mole fractions of the liquid components of each plate is not equal to 1, the calculated liquid component concentration is normalized using the normalization equation, and then the phase equilibrium plate temperature and the phase equilibrium constant are recalculated using the normalized liquid component concentration;

[0034] According to the recalculated phase equilibrium plate temperature and phase equilibrium constant, the gas phase component concentration of each component on each plate is calculated using the phase equilibrium equation group, and the gas phase component concentration of each component on each plate is substituted into the mole fraction addition equation group, and the mole fraction addition equation group is used to determine whether the sum of the mole fractions of the gas phase components of each stage is equal to 1;

[0035] If it is not equal to 1, continue to perform the steps of calculating the phase equilibrium plate temperature and the phase equilibrium constant, and calculating the gas phase component concentration of each component on each plate using the phase equilibrium equation group, until the sum of the gas phase component mole fractions of each stage is equal to 1;

[0036] The phase equilibrium constant is updated, and the liquid phase component concentration of each component on each tower plate is calculated again, and the liquid phase component concentration of each component on each tower plate is substituted into the mole fraction addition equation group, and it is determined whether the sum of the mole fractions of the liquid phase components of each stage is equal to 1, until the sum of the mole fractions of the liquid phase components of each stage is equal to 1.

[0037] According to a simulation calculation method provided by the present invention, the mole fraction summation equation group uses the mole fraction summation equation group to determine whether the sum of the mole fractions of the gas phase components of each stage of the plate is equal to:

[0038]

[0039]

[0040] Among them, x i,j is the liquid component concentration of component i on the jth plate; y i,j is the gas phase component concentration of component i on the jth tower plate.

[0041] According to a simulation calculation method provided by the present invention, the gas phase flow rate is corrected using the heat balance equation group, including:

[0042]

[0043] Among them, h Lj is the liquid phase enthalpy of the mixture on the jth plate; h Fj is the feed enthalpy on the jth plate; h Vj is the gas phase enthalpy of the mixture on the jth plate; Q j is the heat load on the jth plate; L j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j F is the gas phase flow rate extracted from the side line on the jth tower plate; j is the feed flow rate on the jth tower plate.

[0044] The present invention also provides a simulation computing device for cryogenic distillation separation of helium isotopes, comprising:

[0045] Establish a model unit for establishing a mathematical model of a helium isotope cryogenic distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, gas and liquid can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate and the liquid mixture are in a phase equilibrium state; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower comprises N tower plates and M components, and each tower plate serves as an equilibrium stage of the mathematical model; the mathematical model includes a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium stages;

[0046] A parameter determination unit, used to determine initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate;

[0047] A liquid phase determination unit, for solving a component material balance equation group and a phase equilibrium equation group of each component based on the initial parameters by using a tridiagonal matrix method to obtain a liquid phase component concentration of each component on each tray;

[0048] The simulation calculation unit is used to correct the temperature according to the liquid component concentration of each component on each tower plate using the mole fraction addition equation group and correct the gas phase flow rate using the heat balance equation group, and finally simulate the concentration distribution, temperature distribution, flow distribution of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler.

[0049] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the simulation calculation method for separating helium isotopes by cryogenic distillation as described in any one of the above are implemented.

[0050] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the simulation calculation method for separating helium isotopes by cryogenic distillation as described in any one of the above.

[0051] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of any of the above-mentioned simulation calculation methods for cryogenic distillation separation of helium isotopes.

[0052] The present invention provides a simulation calculation method and device for separating helium isotopes by low-temperature distillation. The mathematical model of a helium isotope low-temperature distillation tower is established, and then the mathematical model is input into the model for solving based on determined initial parameters to obtain the liquid component concentration of each component on each tower plate. According to the liquid component concentration of each component on each tower plate, the temperature is corrected by using the mole fraction addition equation group, and the gas phase flow rate is corrected by using the heat balance equation group. Finally, the component concentration, temperature, gas-liquid phase flow rate of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler are simulated. The simulation result has important guiding significance for the selection of experimental parameter conditions and the construction of the device in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 This is one of the flow diagrams of the simulation calculation method for cryogenic distillation separation of helium isotopes provided by the present invention;

[0055] Figure 2 It is a schematic diagram of a cryogenic distillation tower model provided by the present invention;

[0056] Figure 3 This is the second flow diagram of the simulation calculation method for separating helium isotopes by cryogenic distillation provided by the present invention;

[0057] Figure 4 This is the third flow diagram of the simulation calculation method for separating helium isotopes by cryogenic distillation provided by the present invention;

[0058] Figure 5 This is the fourth flow diagram of the simulation calculation method for separating helium isotopes by cryogenic distillation provided by the present invention;

[0059] Figure 6 It is a schematic diagram of the structure of the simulation computing device for cryogenic distillation separation of helium isotopes provided by the present invention;

[0060] Figure 7 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are 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.

[0062] The embodiment of the present invention discloses a simulation calculation method for cryogenic distillation separation of helium isotopes, which mainly includes solving the cryogenic distillation mathematical model MESH and calculating the thermodynamic properties of helium isotopes. Figure 1 ,include:

[0063] 101. Establish a mathematical model of the helium isotope cryogenic distillation tower.

[0064] Among them, the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, the gas and liquid phases can quickly reach equilibrium after contact, that is, the gas mixture leaving the tower plate is in phase equilibrium with the liquid mixture; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition.

[0065] In addition, the model needs to consider the following additional simplifying assumptions:

[0066] 1. The distillation tower is insulated from the outside world;

[0067] 2. Ignore the pressure drop inside the tower.

[0068] The helium isotope cryogenic distillation tower comprises N plates and M components, each plate being a balance stage of a mathematical model; the mathematical model comprises a component material balance equation group M, a phase balance equation group E, a mole fraction summation equation group S and a heat balance equation group H for the N balance stages.

[0069] Specifically, the M equation - component material balance equation group is the following formula (1):

[0070] L j-1 x i,j-1+V j+1 y i,j+1 +F j z i,j -(L j +U j )x i,j -(V j +W j )y i,j =0 (1)

[0071] Among them, L j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; x i，j is the liquid component concentration of component i on the jth plate; y i，j is the gas phase component concentration of component i on the jth tower plate; F j is the feed flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j is the gas phase flow rate extracted from the side line on the jth tower plate.

[0072] E equation - phase equilibrium equation is as follows (2):

[0073] y i，j -K i，j x i，j =0 (2)

[0074] Among them, K i，j is the phase equilibrium constant of component i on the jth tower plate, and the rest are the same as above.

[0075] S equation - the mole fraction summation equations are as follows (3) and (4):

[0076]

[0077]

[0078] H equation - the heat balance equation is as follows (5):

[0079]

[0080] Among them, h Lj is the liquid phase enthalpy of the mixture on the jth plate; h Fj is the feed enthalpy on the jth plate; h Vj is the gas phase enthalpy of the mixture on the jth plate; Q j is the heat load on the jth tower plate; the rest are the same as above.

[0081] In addition, the total material balance formula for the device from level 1 to level j is as follows (6):

[0082]

[0083] Among them, F m is the feed flow rate on the jth plate; U m W is the liquid phase flow rate of the side line on the jth tower plate; m is the gas phase flow rate of the side line on the jth tower plate, L j is the liquid phase flow rate on the jth plate; V 1 is the gas phase flow rate on the first plate, V j+1 is the gas phase flow rate on the j+1th tower plate.

[0084] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a cryogenic distillation tower model in this embodiment. j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; x i,j is the liquid component concentration of component i on the jth plate; y i,j is the gas phase component concentration of component i on the jth tower plate; F j is the feed flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j Q is the gas phase flow rate extracted from the side line on the jth tower plate; j is the heat load on the jth tower plate.

[0085] 102. Determine initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate.

[0086] In this embodiment, to solve each set of equations, it is necessary to formulate appropriate initial values ​​of temperature, phase equilibrium constant, and gas phase flow rate. The quality of the initial value selection directly affects the convergence speed of the program.

[0087] Specifically, see Figure 3 In step 102, the initial parameters are determined including:

[0088] 301. The initial value of each plate temperature is obtained by linear interpolation based on the bubble point temperature of the mixture generated on the top plate and the dew point temperature of the mixture generated on the bottom plate.

[0089] 302. The initial value of the phase equilibrium constant is calculated based on the ideal K-model equation.

[0090] Specifically, the initial value of the phase equilibrium constant is calculated according to the ideal K-model equation, including the following formula (7):

[0091]

[0092] in, is the saturated vapor pressure of component i, and p is the total pressure;

[0093] The components include helium-3 and helium-4. The saturated vapor pressure of helium-3 and helium-4 is calculated by the following formula:

[0094] The saturated vapor pressure formula of helium 4 is as follows (8) to (10):

[0095]

[0096]

[0097]

[0098] The saturated vapor pressure formula of helium 3 is as follows (11):

[0099]

[0100] 303. Determine the initial value of the gas phase flow rate according to the constant molar flow assumption and the heat balance equations, wherein the constant molar flow assumption is that the rising steam molar flow rates in the rectification section and the stripping section are equal.

[0101] The initial value of the gas phase flow rate is determined based on the constant molar flow assumption, that is, the rising steam molar flow rates in the rectification section and the stripping section are equal, but the gas phase molar flow rates in the two sections are not necessarily equal, which depends on the thermal condition of the feed. Therefore, the thermal condition of the feed needs to be determined based on the feed parameters. The steps for determining the thermal condition of the feed are determined based on the heat balance equations.

[0102] 103. Based on the initial parameters, the tridiagonal matrix method is used to solve the component material balance equations and phase equilibrium equations of each component to obtain the liquid phase component concentration of each component on each tower plate.

[0103] The specific steps for solving the ME equations are as follows: Substitute the phase balance equation (2) into the material balance equation (1) to eliminate y i,j , and then substitute formula (6) to eliminate L j After sorting, we get a multivariate linear equation system, which can be easily written into a matrix form, and then the Gaussian elimination method can be used to solve the liquid phase composition x i,j .

[0104] 104. According to the liquid component concentration of each component on each tower plate, the temperature is corrected using the mole fraction summation equation group, and the gas phase flow rate is corrected using the heat balance equation group, and finally the component concentration, temperature, gas-liquid phase flow rate of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler are simulated.

[0105] Among them, the component concentration is calculated according to formulas (1) and (2), the temperature is calculated according to formulas (3) and (4), the gas-liquid flow rate is calculated according to formula (1), and the heat load is calculated according to formula (5).

[0106] The simulation calculation method for low-temperature distillation separation of helium isotopes provided in an embodiment of the present invention establishes a mathematical model of a helium isotope low-temperature distillation tower, and then inputs the mathematical model into the model for solving based on determined initial parameters to obtain the liquid component concentration of each component on each tower plate; according to the liquid component concentration of each component on each tower plate, the temperature is corrected using the mole fraction addition equation group, and the gas phase flow rate is corrected using the heat balance equation group, and finally the component concentration, temperature, gas-liquid phase flow rate of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler are simulated, and the simulation results have important guiding significance for the selection of experimental parameter conditions and the construction of the device in the future.

[0107] Specifically, see Figure 4 In step 104, the temperature is corrected using the mole fraction summation equations according to the liquid component concentration of each component on each tray, including:

[0108] 401. Substitute the solved concentrations of the liquid components of each component on each tower plate into the mole fraction addition equation group to determine whether the sum of the mole fractions of the liquid components on each stage is equal to 1.

[0109] 402. If the sum of the mole fractions of the liquid components of each stage is not equal to 1, the calculated concentration of the liquid components is normalized using the normalization equation, and then the phase equilibrium plate temperature and the phase equilibrium constant are recalculated using the normalized concentration of the liquid components;

[0110] 403. According to the recalculated phase equilibrium plate temperature and phase equilibrium constant, the gas phase component concentration of each component on each plate is calculated using the phase equilibrium equation group, and the gas phase component concentration of each component on each plate is substituted into the mole fraction addition equation group, and the mole fraction addition equation group is used to determine whether the sum of the mole fractions of the gas phase components of each stage is equal to 1;

[0111] 404. If it is not equal to 1, continue to perform the steps of calculating the phase equilibrium plate temperature and the phase equilibrium constant, and calculating the gas phase component concentration of each component on each plate using the phase equilibrium equation group, until the sum of the gas phase component mole fractions of each stage is equal to 1;

[0112] 405. Update the phase equilibrium constant, recalculate the concentration of the liquid phase component of each component on each tower plate, substitute the solved concentration of the liquid phase component of each component on each tower plate into the mole fraction addition equation group, and determine whether the sum of the mole fractions of the liquid phase components of each stage is equal to 1, until the sum of the mole fractions of the liquid phase components of each stage is equal to 1.

[0113] The normalized equation is shown in equation (7):

[0114]

[0115] After the temperature is corrected using the S equation, the next step is to correct the gas phase flow using the H equation, that is, correcting the gas phase flow using the heat balance equation group in step 104.

[0116] First, it is necessary to calculate the gas-liquid phase molar enthalpy of the mixture on each level of the tower plate, as well as the enthalpy of the feed. Due to the particularity of the helium element, at low temperatures, there is currently no state equation that can well describe its thermodynamic properties. Directly using the general SRK, PR or BWM state equations can easily cause the program iteration to oscillate and be difficult to converge. In this regard, the embodiment of the present invention uses the least squares method to fit the saturated gas-liquid enthalpy data of helium 3 within the temperature range into a function of temperature. Similarly, the saturated gas-liquid enthalpy of helium 4 is also treated in this way. However, since the superfluid helium transition temperature of helium 4 is 2.17K, within the range of distillation temperature, when helium 4 is converted to superfluid helium, its enthalpy will have a corresponding inflection point. Therefore, the embodiment of the present invention segmentally fits the enthalpy data of helium 4 before and after the superfluid helium transition to ensure the accuracy of the fitting equation.

[0117] See also Figure 5 , Figure 5 A simulation calculation method for separating helium isotopes by cryogenic distillation disclosed in an embodiment of the present invention is shown, comprising:

[0118] S1. Pre-define F j - Feed flow rate of each tray, z i，j - Light component concentration and feed conditions of each tray feed (T Fj - Feed temperature of each tray, P Fj - Feed pressure of each tray, or h Fj -enthalpy of the feed mixture at each tray), P j -Pressure on each plate, U j -Liquid phase extraction flow rate on each layer of the tower plate, W j -Gas phase extraction flow rate on each layer of the tower plate; Q j -Heat load on each tray except Q l - Heat load of the condenser (i.e. layer 1) and Q N-Heat load of reboiler (i.e. Nth layer); N-theoretical plate number, R-reflux ratio, V 1 -Gas phase extraction flow rate on the first tower plate (condenser).

[0119] The method of this embodiment requires solving the MESH equation, and it is necessary to formulate a suitable initial value of temperature Tj and initial value of phase equilibrium constant K i,j And the initial value of gas flow V j 0 ,The quality of the initial value selection directly affects the convergence speed of the program.

[0120] First, the initial value of each plate temperature is obtained by linear interpolation of the bubble point temperature of the top product composition and the dew point temperature of the bottom product composition. Using the properties of the mixture bubble dew point, the steps for calculating the top bubble point temperature and the bottom dew point temperature are written into subroutines PB and PD respectively. The recalculation of the plate temperature also uses the bubble point calculation method, and is iteratively updated using the Newton interpolation method until the criterion meets the requirements. Secondly, due to the lack of gas-liquid phase equilibrium constants of helium-3 and helium-4, as well as available thermodynamic state equations, the initial value of the phase equilibrium constant is calculated using the ideal K-model equation, see formula (7). The steps for calculating the gas-liquid phase equilibrium constants of helium-3 and helium-4, namely formulas (8) to (11), are written into subroutine K34.

[0121] S2, set the initial temperature value T j , and the initial value of gas phase flow rate V j 0 .

[0122] S3. Call in K34 program to calculate the initial value of phase equilibrium constant K i,j .

[0123] After the initial parameters are determined, the MESH equations can be calculated.

[0124] A simulation calculation method for low-temperature distillation separation of helium isotopes is a method of grouping the MESH equations by type. Under certain initial values ​​of temperature and vapor phase flow rate, the tridiagonal matrix method is used to solve the ME equations for each component, and then the S-equation is used to correct the temperature and the H-equation is used to correct the vapor phase flow rate. Finally, the component concentration, temperature, flow rate and heat load of the helium isotope that meets the conditions are obtained.

[0125] The specific steps for solving the ME equations are as follows: Substituting the phase balance equation (2) into the material balance equation (1), the gas phase component concentration y of component i on the jth plate can be eliminated. i,j , and then substitute equation (6) to eliminate L j After sorting, we get a multivariate linear equation system, which can be easily written into a matrix form. Then, the Gaussian elimination method can be used to solve the liquid component concentration x of the liquid component i on the jth tower plate.i,j . Substitute the above solution steps x i，j Compile it into a subroutine and name it ME.

[0126] S4. Transfer the ME program to calculate the liquid component concentration x i，j .

[0127] S5. Liquid components x of each plate calculated using ME subroutine i，j Substitute into the S equation (4) to determine whether the sum of the mole fractions of the liquid components of each stage is equal to 1.

[0128] S6. If it is not equal to 1, use the normalization equation (7) to calculate x i，j Perform normalization.

[0129] S7. Use the normalized x i，j , recalculate the phase equilibrium plate temperature Tj and the phase equilibrium constant K i，j Among them, the step of calculating the phase equilibrium tower plate temperature has been written as a subroutine TB.

[0130] S8. Use E equation to calculate the gas phase composition y of each plate i，j , and use S equation (3) to determine whether the sum of the mole fractions of the gas phase components of each stage is equal to 1.

[0131] If it is not equal to 1, continue to execute step S7, calculate the phase equilibrium tower plate temperature and the phase equilibrium constant, and use the phase equilibrium equation group to calculate the gas phase component concentration of each component on each tower plate until the sum of the mole fractions of the gas phase components of each stage is equal to 1.

[0132] S9, update the phase equilibrium constant, recalculate the liquid component concentration of each component on each tower plate, substitute the solved liquid component concentration of each component on each tower plate into the mole fraction summation equation group, and determine whether the sum of the mole fractions of the liquid components of each stage is equal to 1, until the sum of the mole fractions of the liquid components of each stage is equal to 1.

[0133] After correcting the temperature using the S equation, the next step is to correct the vapor phase flow rate using the H equation. First, it is necessary to calculate the gas-liquid phase molar enthalpy of the mixture on each stage of the tower plate, as well as the enthalpy of the feed. Due to the particularity of the helium element, at low temperatures, there is currently no state equation that can well describe its thermodynamic properties. Directly using the general SRK, PR or BWM state equations can easily cause the program iteration to oscillate and be difficult to converge. In this regard, the present invention uses the least squares method to fit the saturated gas-liquid enthalpy data of helium 3 within the temperature range into a function of temperature. Similarly, the saturated gas-liquid enthalpy of helium 4 is also treated in this way. However, since the superfluid helium transition temperature of helium 4 is 2.17K, within the range of distillation temperature, when helium 4 is converted to superfluid helium, its enthalpy will have a corresponding inflection point. Therefore, the present invention fits the enthalpy data of helium 4 before and after the superfluid helium transition in sections to ensure the accuracy of the fitting equation. The above-mentioned steps of calculating the gas-liquid phase molar enthalpy of the mixture on each stage of the tower plate are written as a subroutine and named Hmix. Write the steps for calculating the feed enthalpy into a subroutine and name it FeedH.

[0134] S10, transfer the FeedH and Hmix programs to calculate the feed enthalpy value h fj , liquid phase enthalpy h Lj and the gas phase enthalpy h Vj .

[0135] S11. By solving the H equation, the heat load Q of the top condenser can be obtained respectively. 1 , heat load Q of the bottom reboiler N and the gas phase flow rate V on the plate j (k) The steps for calculating the gas phase flow rate and heat load are written into a subroutine and named VandQ. Finally, the liquid phase flow rate on the tower plate can be calculated accordingly by equation (6).

[0136] S12, calculate whether the interval accuracy value of the gas phase flow is less than the set threshold. If so, end directly. If not, update the gas phase flow value on each tower plate and start the next iterative calculation of steps S4 to S12.

[0137] Among them, the interval accuracy of gas phase flow is |(V j (k+1) -V j (k) ) / V j (k+1) |. In step S12, |(V j (k+1) -V j (k) ) / V j (k+1) |Is it less than the set threshold value e3? If not, update the gas phase flow value on each layer of the tower plate to Vj (k+1) =0.5(V j (k+1) +V j (k) ).

[0138] In addition, the boundary conditions that need to be set in this method are shown in Table 1. Using this method, after entering the boundary conditions, the component concentration, temperature, gas-liquid flow rate, and heat load in the condenser and reboiler on the helium isotope cryogenic distillation tower can be simulated. The specific values ​​in Table 1 are used as examples, and the actual simulation can be changed accordingly.

[0139] Table 1 Setting parameters

[0140]

[0141]

[0142] Helium isotopes are the gas with the lowest boiling point temperature at present. The boiling point of helium 4 is 4.2K, and the boiling point of helium 3 is 3.19K. Its physical properties at low temperature are difficult to be uniformly described by the equation of state. The vapor-liquid equilibrium data is particularly lacking. It is difficult to realize the distillation simulation of helium isotopes using the chemical process simulation software (Aspen Plus, Chemcad, etc.) on the market. A simulation calculation method for separating helium isotopes by low-temperature distillation is provided in an embodiment of the present invention. The thermodynamic data of helium isotopes at low temperature are fitted into a usable equation for program call using the least squares method; the solution steps for solving the MESH equation are sequentially written into subroutines, and finally the mathematical model of the helium isotope low-temperature distillation tower can be successfully solved using the total program. Using this calculation method, according to the set boundary conditions, the concentration distribution, temperature distribution, flow distribution of helium isotopes in the distillation tower and the heat load of the condenser and reboiler can be simulated.

[0143] The simulation calculation device for cryogenic distillation separation of helium isotopes provided by the present invention is described below. The simulation calculation device for cryogenic distillation separation of helium isotopes described below and the simulation calculation method for cryogenic distillation separation of helium isotopes described above can be referenced to each other.

[0144] The embodiment of the present invention discloses a simulation computing device for separating helium isotopes by cryogenic distillation, see Figure 6 ,include:

[0145] A model building unit 601 is used to build a mathematical model of a helium isotope cryogenic distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, the gas and liquid two-phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate and the liquid mixture are in a phase equilibrium state; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower comprises N tower plates and M components, and each tower plate serves as an equilibrium stage of the mathematical model; the mathematical model includes a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium stages;

[0146] A parameter determination unit 602 is used to determine initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate;

[0147] A liquid phase determination unit 603 is used to solve the component material balance equations and phase equilibrium equations of each component based on the initial parameters using a tridiagonal matrix method to obtain the liquid phase component concentration of each component on each tray;

[0148] The simulation calculation unit 604 is used to correct the temperature using the mole fraction summation equation group according to the liquid component concentration of each component on each tower plate, and correct the gas phase flow rate using the heat balance equation group, and finally simulate the concentration distribution, temperature distribution, flow distribution of helium isotopes in the distillation tower, and the heat load of the top condenser and the bottom reboiler.

[0149] Optionally, the parameter determination unit 602 is specifically configured to:

[0150] The initial value of each tray temperature is obtained by linear interpolation based on the bubble point temperature of the mixture generated on the tray at the top of the tower and the dew point temperature of the mixture generated on the tray at the bottom of the tower;

[0151] The initial value of the phase equilibrium constant is calculated based on the ideal K-model equation;

[0152] The initial value of the gas phase flow rate is determined according to the constant molar flow assumption and the heat balance equations, wherein the constant molar flow assumption is that the rising steam molar flows in the rectifying section and the stripping section are equal.

[0153] Optionally, the simulation calculation unit 604 is specifically used for:

[0154] Substitute the solved concentration of the liquid phase components on each plate into the mole fraction addition equation group to determine whether the sum of the mole fractions of the liquid phase components on each plate is equal to 1;

[0155] If the sum of the mole fractions of the liquid components of each plate is not equal to 1, the calculated liquid component concentration is normalized using the normalization equation, and then the phase equilibrium plate temperature and the phase equilibrium constant are recalculated using the normalized liquid component concentration;

[0156] According to the recalculated phase equilibrium plate temperature and phase equilibrium constant, the gas phase component concentration of each component on each plate is calculated using the phase equilibrium equation group, and the gas phase component concentration of each component on each plate is substituted into the mole fraction addition equation group, and the mole fraction addition equation group is used to determine whether the sum of the mole fractions of the gas phase components of each stage is equal to 1;

[0157] If it is not equal to 1, continue to perform the steps of calculating the phase equilibrium plate temperature and the phase equilibrium constant, and calculating the gas phase component concentration of each component on each plate using the phase equilibrium equation group, until the sum of the gas phase component mole fractions of each stage is equal to 1;

[0158] The phase equilibrium constant is updated, and the liquid phase component concentration of each component on each tower plate is calculated again, and the liquid phase component concentration of each component on each tower plate is substituted into the mole fraction addition equation group, and it is determined whether the sum of the mole fractions of the liquid phase components of each stage is equal to 1, until the sum of the mole fractions of the liquid phase components of each stage is equal to 1.

[0159] Figure 7 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 7As shown, the electronic device may include: a processor 710, a communication interface 720, a memory 730 and a communication bus 740, wherein the processor 710, the communication interface 720 and the memory 730 communicate with each other through the communication bus 740. The processor 710 may call the logic instructions in the memory 730 to execute the simulation calculation method for separating helium isotopes by cryogenic distillation, including: establishing a mathematical model of a helium isotope cryogenic distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: assuming that on each tower plate, the gas and liquid two-phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate is in a phase equilibrium state with the liquid mixture; assuming that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower includes N tower plates and M components, each tower plate is used as an equilibrium level of the mathematical model; the mathematical model includes for N equilibrium The method comprises the following steps: determining the component material balance equations, the phase equilibrium equations, the mole fraction summation equations and the heat balance equations of the first stage; determining the initial parameters, wherein the initial parameters include the initial value of temperature, the initial value of phase equilibrium constant and the initial value of gas phase flow rate; solving the component material balance equations and the phase equilibrium equations of each component based on the initial parameters by using the tridiagonal matrix method to obtain the liquid component concentration of each component on each tower plate; correcting the temperature by using the mole fraction summation equations according to the liquid component concentration of each component on each tower plate, and correcting the gas phase flow rate by using the heat balance equations, and finally simulating the component concentration, temperature, gas-liquid phase flow rate and heat load of the top condenser and the bottom reboiler of the helium isotope in the distillation tower.

[0160] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0161] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the simulation calculation method for low-temperature distillation separation of helium isotopes provided by the above methods, including: establishing a mathematical model of a helium isotope low-temperature distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: assuming that on each tower plate, the gas and liquid two phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate is in a phase equilibrium state with the liquid mixture; assuming that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope low-temperature distillation tower comprises N tower plates and M groups The method comprises the following steps: dividing the tower plate into two parts, each tower plate being an equilibrium level of the mathematical model; the mathematical model comprising a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium levels; determining initial parameters, wherein the initial parameters comprise an initial value of temperature, an initial value of phase equilibrium constant and an initial value of gas phase flow rate; based on the initial parameters, solving the group of component material balance equations and the group of phase balance equations for each component by using a tridiagonal matrix method to obtain a liquid phase component concentration of each component on each tower plate; according to the liquid phase component concentration of each component on each tower plate, correcting the temperature by using the group of mole fraction summation equations, and correcting the gas phase flow rate by using the group of heat balance equations, and finally simulating the component concentration, temperature, gas-liquid phase flow rate and heat load of a top condenser and a bottom reboiler of helium isotopes in the distillation tower.

[0162] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the simulation calculation method for low-temperature distillation separation of helium isotopes provided by the above methods, including: establishing a mathematical model of a helium isotope low-temperature distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: assuming that on each tower plate, the gas and liquid two-phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate is in a phase equilibrium state with the liquid mixture; assuming that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope low-temperature distillation tower comprises N tower plates and M components, and each tower plate is used as a component of the mathematical model. equilibrium stage; the mathematical model includes a group of component material balance equations, a group of phase equilibrium equations, a group of mole fraction summation equations and a group of heat balance equations for N equilibrium stages; initial parameters are determined, wherein the initial parameters include an initial value of temperature, an initial value of phase equilibrium constant and an initial value of gas phase flow rate; based on the initial parameters, the group of component material balance equations and the group of phase equilibrium equations of each component are solved by a tridiagonal matrix method to obtain the liquid component concentration of each component on each tower plate; according to the liquid component concentration of each component on each tower plate, the temperature is corrected by the group of mole fraction summation equations, and the gas phase flow rate is corrected by the group of heat balance equations, and finally the component concentration, temperature, gas-liquid phase flow rate and heat load of the top condenser and the bottom reboiler of helium isotopes in the distillation tower are simulated.

[0163] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0164] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulation calculation method for the separation of helium isotopes by cryogenic distillation. It is characterized in that include: A mathematical model of a helium isotope cryogenic distillation tower is established, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, the gas and liquid two-phases can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate is in a phase equilibrium state with the liquid mixture; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower comprises N tower plates and M components, and each tower plate serves as an equilibrium stage of the mathematical model; the mathematical model comprises a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium stages; Determining initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate; Based on the initial parameters, a tridiagonal matrix method is used to solve a component material balance equation group and a phase equilibrium equation group of each component to obtain a liquid phase component concentration of each component on each tray; According to the liquid phase component concentration of each component on each tower plate, the temperature is corrected using the mole fraction addition equation group, and the gas phase flow rate is corrected using the heat balance equation group, and finally the component concentration, temperature, gas-liquid phase flow rate of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler are simulated.

2. The simulation calculation method according to claim 1, It is characterized in that Determine initial parameters, including: The initial value of each tray temperature is obtained by linear interpolation based on the bubble point temperature of the mixture generated on the tray at the top of the tower and the dew point temperature of the mixture generated on the tray at the bottom of the tower; The initial value of the phase equilibrium constant is calculated based on the ideal K-model equation; The initial value of the gas phase flow rate is determined according to the constant molar flow assumption and the heat balance equations, wherein the constant molar flow assumption is that the rising steam molar flows in the rectifying section and the stripping section are equal.

3. The simulation calculation method according to claim 2, It is characterized in that The initial value of the phase equilibrium constant is calculated according to the ideal K-model equation, including: in, is the saturated vapor pressure of component i, and p is the total pressure; The components include helium-3 and helium-4. The saturated vapor pressure of helium-3 and helium-4 is calculated by the following formula: The formula for the saturated vapor pressure of helium-4 is: The formula for the saturated vapor pressure of helium-3 is: Among them, p represents the saturated vapor pressure of helium 4 and helium 3, pc represents the critical pressure of helium 4, and a k represents the coefficient for calculating the saturated vapor pressure of helium 3, T represents the temperature, T c represents the critical temperature of helium-4, θ represents the dimensionless temperature number established using Tc, and b represents the coefficient for calculating the saturated vapor pressure of helium-3.

4. The simulation calculation method according to claim 1, It is characterized in that The component material balance equations are implemented by the following formula: L j-1 x i，j-1 +V j+1 y i，j+1 +F j z i，j -(L j +U j )x i，j -(V j +W j )y i，j =0 Among them, L j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; x i,j is the liquid component concentration of component i on the jth plate; y i,j is the gas phase component concentration of component i on the jth tower plate; F j is the feed flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j is the gas phase flow rate extracted from the side line on the jth tower plate; The phase equilibrium equations are implemented by the following formula: and i，j -K i，j x i,j =0 Among them, K i,j is the phase equilibrium constant of component i on the jth tower plate.

5. The simulation calculation method according to claim 1, It is characterized in that The temperature is corrected using the mole fraction summation equations according to the liquid phase component concentration of each component on each tray, including: Substitute the solved concentration of the liquid phase components on each plate into the mole fraction addition equation group to determine whether the sum of the mole fractions of the liquid phase components on each plate is equal to 1; If the sum of the mole fractions of the liquid components of each plate is not equal to 1, the calculated liquid component concentration is normalized using the normalization equation, and then the phase equilibrium plate temperature and the phase equilibrium constant are recalculated using the normalized liquid component concentration; According to the recalculated phase equilibrium plate temperature and phase equilibrium constant, the gas phase component concentration of each component on each plate is calculated using the phase equilibrium equation group, and the gas phase component concentration of each component on each plate is substituted into the mole fraction addition equation group, and the mole fraction addition equation group is used to determine whether the sum of the mole fractions of the gas phase components of each stage is equal to 1; If it is not equal to 1, continue to perform the steps of calculating the phase equilibrium plate temperature and the phase equilibrium constant, and calculating the gas phase component concentration of each component on each plate using the phase equilibrium equation group, until the sum of the gas phase component mole fractions of each stage is equal to 1; The phase equilibrium constant is updated, and the liquid phase component concentration of each component on each tower plate is calculated again, and the liquid phase component concentration of each component on each tower plate is substituted into the mole fraction addition equation group, and it is determined whether the sum of the mole fractions of the liquid phase components of each stage is equal to 1, until the sum of the mole fractions of the liquid phase components of each stage is equal to 1.

6. The simulation calculation method according to claim 5, It is characterized in that The mole fraction summation equations include: Among them, x i,j is the liquid component concentration of component i on the jth plate; y i,j is the gas phase component concentration of component i on the jth tower plate.

7. The simulation calculation method according to claim 1, It is characterized in that Correcting the gas phase flow rate using the heat balance equations includes: Among them, h Lj is the liquid phase enthalpy of the mixture on the jth plate; h Fj is the feed enthalpy on the jth plate; h Vj is the gas phase enthalpy of the mixture on the jth plate; Q j is the heat load on the jth plate; L j is the liquid phase flow rate on the jth plate; V j is the gas phase flow rate on the jth plate; U j W is the liquid phase flow rate of the side line on the jth tower plate; j F is the gas phase flow rate of the side line on the jth tower plate; j is the feed flow rate on the jth tower plate.

8. A simulation computing device for separating helium isotopes by cryogenic distillation. It is characterized in that include: Establish a model unit for establishing a mathematical model of a helium isotope cryogenic distillation tower, wherein the mathematical model is based on the assumptions of theoretical plates and fully mixed plates: it is assumed that on each tower plate, gas and liquid can quickly reach an equilibrium state after contact, that is, the gas mixture leaving the tower plate and the liquid mixture are in a phase equilibrium state; it is assumed that the liquid on each tower plate and the gas between the tower plates are completely mixed and have uniform pressure, temperature and composition; the helium isotope cryogenic distillation tower comprises N tower plates and M components, and each tower plate serves as an equilibrium stage of the mathematical model; the mathematical model includes a group of component material balance equations, a group of phase balance equations, a group of mole fraction summation equations and a group of heat balance equations for the N equilibrium stages; A parameter determination unit, used to determine initial parameters, wherein the initial parameters include an initial value of temperature, an initial value of a phase equilibrium constant, and an initial value of a gas phase flow rate; A liquid phase determination unit, for solving a component material balance equation group and a phase equilibrium equation group of each component based on the initial parameters by using a tridiagonal matrix method to obtain a liquid phase component concentration of each component on each tray; The simulation calculation unit is used to correct the temperature according to the liquid component concentration of each component on each tower plate using the mole fraction addition equation group and correct the gas phase flow rate using the heat balance equation group, and finally simulate the concentration distribution, temperature distribution, flow distribution of helium isotopes in the distillation tower and the heat load of the top condenser and the bottom reboiler.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, It is characterized in that When the processor executes the program, the steps of the simulation calculation method for separating helium isotopes by cryogenic distillation are implemented as claimed in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, It is characterized in that When the computer program is executed by a processor, the steps of the simulation calculation method for cryogenic distillation separation of helium isotopes as claimed in any one of claims 1 to 7 are implemented.

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