Solubility calculation method and apparatus, and storage medium

Abstract

The present invention provides a solubility calculation method, a solubility calculation apparatus, and a computer-readable storage medium. The solubility calculation method comprises the following steps: setting initial molar fractions, initial temperatures, and initial pressures of a plurality of components in two phases, i.e., a gas phase and a liquid phase, substance parameters of the components, and binary interaction parameters among the components in an olefin polymerization system, the sum of the initial molar fractions of the components being 1 in both the gas phase and the liquid phase; calculating the fugacities of the components in the two phases, i.e., the gas phase and the liquid phase, and, on the basis of same, setting fugacity-related gas-liquid phase equilibrium conditions; and, in response to the molar fractions of the components satisfying the gas-liquid phase equilibrium conditions, and on the basis of the molar fraction of at least one liquid phase component, solving for the solubility thereof in the olefin polymerization system. The present invention can be used for solving the problem of gas-liquid phase equilibrium of a mixture of a plurality of components, so as to quickly and accurately converge to a phase equilibrium point.

Description

Solubility calculation method, device and storage medium TECHNICAL FIELD

[0001] The present application relates to the field of thermodynamics, in particular to a solubility calculation method, a solubility calculation device and a computer readable storage medium. BACKGROUND

[0002] A phase equilibrium calculation method is a method for predicting the distribution of each component in different phases (such as solid, liquid, gas) in a chemical system. Traditional phase equilibrium calculation methods are usually based on state equations and mixing rules, but these methods have certain limitations in dealing with multi-component mixtures and polar molecules. In the analysis of vapor-liquid phase equilibrium of multi-component mixtures, commonly used methods include non-ideal solution models, activity coefficient models and equation of state models. However, the applicability of non-ideal solution models is limited, especially in dealing with complex systems such as high concentration and polar solutions, which may not perform well. The parameterization of the activity coefficient model is complex, usually requiring a large amount of experimental data and complex optimization algorithms to determine the model parameters, and lacks accuracy for new components or special systems. The equation of state model has limited ability to describe non-idealities, ignoring other important non-ideal factors such as polarization effects and hydrogen bond formation. In addition, the commonly used methods for solving multi-component vapor-liquid phase equilibrium include flash calculation algorithm, trial-error method, bisection method, etc., which have the problems of more iteration steps, slow convergence speed, high computational complexity and possible convergence to local optimal solution, etc., resulting in unsatisfactory performance in dealing with multi-component phase equilibrium calculation.

[0003] In order to overcome the above-mentioned defects existing in the prior art, there is an urgent need in the field for an improved solubility calculation method for solving the vapor-liquid phase equilibrium problem of multi-component mixtures, so as to quickly and accurately converge to the phase equilibrium point. SUMMARY

[0004] The following gives a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an exhaustive overview of all contemplated aspects, and neither is it intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description given later.

[0005] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a solubility calculation method, a solubility calculation device and a computer readable storage medium, which can add perturbations to the mole fractions of each component respectively, construct a multi-dimensional Jacobian partial derivative matrix, and update each component synchronously, for solving the vapor-liquid phase equilibrium problem of multi-component mixtures, so as to quickly and accurately converge to the phase equilibrium point.

[0006] Specifically, the solubility calculation method according to the first aspect of the present application comprises the following steps: setting initial molar fractions of a plurality of components in a gas-liquid two-phase of an olefin polymerization system, an initial temperature, an initial pressure, material parameters of each of the components, and binary interaction parameters between each of the components. The sum of the initial molar fractions of each of the components in the gas-liquid two-phase is 1; calculating fugacities of each of the components in the gas-liquid two-phase, and setting a fugacity-related gas-liquid phase equilibrium condition according to the fugacities; and in response to the molar fractions of each of the components satisfying the gas-liquid phase equilibrium condition, solving the solubility of at least one liquid-phase component in the olefin polymerization system according to the molar fraction of the liquid-phase component.

[0007] Further, in some embodiments of the present application, the material parameters include a segment number m, a segment diameter σ, and / or a segment energy ε / kb of the corresponding component. The binary interaction parameters κ ij are functions of temperature T.

[0008] Further, in some embodiments of the present application, before calculating the fugacities of each of the components in the gas-liquid two-phase, the solubility calculation method further comprises the following steps: solving an equilibrium equation that the pressure of the gas-liquid two-phase must satisfy by using a residual Helmholtz energy model of the PC-SAFT according to a thermodynamic equilibrium condition F, and iteratively adjusting a packing factor of the equilibrium equation to determine whether the model can accurately predict the actual pressure of the olefin polymerization system; and in response to a determination result that the model cannot accurately predict the actual pressure of the olefin polymerization system, adjusting an initial value of the packing factor and iteratively adjusting the packing factor of the equilibrium equation to determine whether the model can accurately predict the actual pressure of the olefin polymerization system.

[0009] Further, in some embodiments of the present application, the equilibrium equation is expressed as:

[0010] P cal (η)=Zk B Tρ

[0011] wherein F is the thermodynamic equilibrium condition. P cal is the actual pressure. P sys is the initial pressure. η is the packing factor. Z is the compressibility factor. k B is the Boltzmann constant. T is the temperature. ρ is the molecular density.

[0012] The step of iteratively adjusting the packing factor of the equilibrium equation is expressed as:

[0013] wherein n is the number of iterations. F' is the first-order derivative of F with respect to η.

[0014] Further, in some embodiments of the present application, the step of calculating the fugacity of each of the components in the gas and liquid phases and setting the fugacity-related gas-liquid phase equilibrium condition according to the calculation is represented as:

[0015] wherein f i I is the fugacity of component i in the gas phase. f i II is the fugacity of component i in the liquid phase. is the mole fraction of component i in the gas phase. is the mole fraction of component i in the liquid phase. is the fugacity coefficient of component i in the gas phase. is the fugacity coefficient of component i in the liquid phase. fvekis the gas-liquid phase equilibrium condition.

[0016] Further, in some embodiments of the present application, the step of calculating the fugacity of each of the components in the gas and liquid phases and setting the fugacity-related gas-liquid phase equilibrium condition according to the calculation is represented as:

[0017] Further, in some embodiments of the present application, the step of iteratively updating the mole fraction of each of the liquid-phase components in response to the mole fraction of each of the components not satisfying the gas-liquid phase equilibrium condition comprises adding a perturbation to each of the liquid-phase components to respectively calculate the partial derivative of the fugacity difference between the liquid phase and the gas phase with respect to the mole fraction of the liquid phase J(g, h):

[0018] wherein, is the mole fraction of component h in the liquid phase after adding a perturbation. σ is a small perturbation, f IInewh is the fugacity of component h in the liquid phase after adding a perturbation. J(g, h) is the partial derivative of the fugacity difference between the liquid phase and the gas phase with respect to the mole fraction of the liquid phase; a Jacobian matrix is constructed according to the set of partial derivatives of each of the liquid-phase components, and the mole fraction of each of the liquid-phase components is iteratively updated according to the Jacobian matrix:

[0019] wherein n is the number of iterations.

[0020] Further, in some embodiments of the present application, in the process of iteratively updating the mole fraction of each of the liquid-phase components according to the Jacobian matrix, the solubility calculation method further comprises the following steps: in response to the update of the mole fraction of each of the liquid-phase components, first performing non-negativity processing and normalization processing on each of the mole fractions, and then performing the next round of iteration:

[0021] Further, in some embodiments of the present application, the step of solving the solubility of the at least one liquid component in the olefin polymerization system according to the mole fraction of the at least one liquid component is expressed as:

[0022] wherein S is the sum of the mass fraction of all monomers. Sx(i) is the mass fraction of each monomer i. Sam(i) is the ratio of the mass fraction of monomer i Sx(i) to the mass fraction of the polymer. mw i is the molecular weight of component i.

[0023] Further, the solubility calculation device according to the second aspect of the present application comprises a memory and a processor. The memory has computer instructions stored thereon. The processor is connected to the memory and is configured to execute the computer instructions stored on the memory to implement the solubility calculation method according to the first aspect of the present application.

[0024] Further, the computer readable storage medium according to the third aspect of the present application has computer instructions stored thereon. The computer instructions are executed by a processor to implement the solubility calculation method according to the first aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above features and advantages of the present application can be better understood by reading the following detailed description of embodiments of the present application in conjunction with the drawings, in which: In the drawings, components are not necessarily drawn to scale and components of similar or identical function or structure can be designated with like reference numerals or letters.

[0026] Fig. 1 shows a flowchart of a solubility calculation method according to some embodiments of the present application.

[0027] Fig. 2 shows a flowchart of an iterative update of the mole coefficient according to some embodiments of the present application.

[0028] Fig. 3 shows a pressure-solubility curve of ethylene, propylene in isotactic polypropylene at 343.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0029] Fig. 4 shows a pressure-solubility curve of ethylene, propylene in isotactic polypropylene at 363.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0030] Fig. 5 shows a pressure-solubility curve of ethylene, 1-hexene in LLDPE at 343.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0031] Figure 6 shows the pressure-solubility curve of ethylene, 1-hexene in LLDPE at 363.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0032] Figure 7 shows the pressure-solubility curve of ethylene, 1-hexene in LLDPE at 423.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0033] Figure 8 shows the pressure-solubility curve of propylene, H2 in PP at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. DETAILED DESCRIPTION

[0034] The specific embodiments of the present application will now be described in detail with specific reference being made to the figures. The following detailed description is disclosed with reference to the attached drawings. In the description of the drawings, the following terms have the following meanings. The figures are not drawn to scale. The figures are provided to illustrate the present application and to provide a better understanding of the principles of the present application. The present application can be better understood by reference to the following description taken in connection with the accompanying drawings, wherein:

[0035] In the description of the present application, it is necessary to point out that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In addition, "up", "down", "left", "right", "top", "bottom", "horizontal", "vertical" used in the following description should be understood as the orientation shown in the paragraph and the related drawings. The relative terms are only used for the convenience of description, and they do not mean that the devices described should be manufactured or operated in a specific orientation, so they should not be understood as a limitation of the present application.

[0037] It is to be understood that, while the terms "first," "second," "third," etc. can be used herein to describe various components, regions, layers and / or sections, these components, regions, layers and / or sections should not be limited by these terms. These terms are simply used to distinguish one component, region, layer or section from another. Thus, a first component, region, layer or section discussed below could be termed a second component, region, layer or section without departing from the scope of some embodiments of the present application.

[0038] As described above, the applicability of the non-ideal solution model has limitations, especially when dealing with complex systems such as high concentration and polar solutions, it may not perform well. The parameterization of the activity coefficient model is complex, usually requires a large amount of experimental data and complex optimization algorithm to determine the model parameters, and lacks accuracy for new components or special systems. The equation of state model has limited ability to describe non-ideality, ignoring other important non-ideal factors such as polarization effect and hydrogen bond formation. In addition, the commonly used methods for solving the phase equilibrium of multi-component vapor-liquid include flash algorithm, trial-error method, dichotomy method, etc., which have many iteration steps, slow convergence speed, high computational complexity, and may converge to local optimal solution, etc., resulting in unsatisfactory results in dealing with multi-component phase equilibrium calculation.

[0039] In order to overcome the above-mentioned defects existing in the prior art, the present application provides a solubility calculation method, a solubility calculation device and a computer readable storage medium, which can add perturbations to the mole fractions of multiple components respectively, construct a multi-dimensional Jacobian partial derivative matrix, and update each component synchronously, to solve the vapor-liquid phase equilibrium problem of multi-component mixture, so as to quickly and accurately converge to the phase equilibrium point.

[0040] In some non-limiting embodiments, the solubility calculation method provided by the first aspect of the present application can be implemented based on the solubility calculation device provided by the second aspect of the present application. Specifically, the solubility calculation device can be configured with a memory and a processor. The memory includes but is not limited to the above-mentioned computer readable storage medium provided by the third aspect of the present application, and the computer instructions are stored on the memory. The processor is connected to the memory and is configured to execute the computer instructions stored on the memory to implement the above-mentioned solubility calculation method provided by the first aspect of the present application.

[0041] For details, please refer to FIG. 1. FIG. 1 shows a flowchart of a solubility calculation method according to some embodiments of the present application.

[0042] As shown in FIG. 1, the processor can first set the initial mole fractions of multiple components in the olefin polymerization system in the gas and liquid phases initial temperature T, initial pressure P sys , material parameters of each component, and binary interaction parameters κ between each componentij Here, the sum of the initial molar fractions of each component in the gas and liquid phases is 1.

[0043] Further, in some embodiments, the above-mentioned substance parameters include the segment number m, segment diameter σ and / or segment energy ε / kb of the corresponding component, for describing the properties of the corresponding component. The above-mentioned binary interaction parameter κ ij is a function of temperature T.

[0044] Then, the processor can derive the thermal relation from the thermodynamic equilibrium condition F, by using the residual Helmholtz energy model of the PCSAFT:

[0045] Pcal(η)=Zk B Tρ

[0046] where a res is the hard-chain reference term of the residual Helmholtz energy model of the PCSAFT.

[0047] Further, the processor can solve the equilibrium equation that the pressures of the gas and liquid phases must satisfy:

[0048] P cal (η)=Zk B Tρ

[0049] where F is the thermodynamic equilibrium condition, P cal is the actual pressure, P sys is the initial pressure, η is the packing factor, Z is the compressibility factor, k B is the Boltzmann constant, T is the temperature, and ρ is the molecular density.

[0050] Further, the processor can iterate the packing factor of the equilibrium equation to determine whether the model can accurately predict the actual pressure of the olefin polymerization system:

[0051] where n is the iteration number, and F' is the first derivative of F with respect to η.

[0052] Further, in response to the determination that the model cannot accurately predict the actual pressure of the olefin polymerization system, i.e., F(η n )≤10 -10 is not satisfied, the processor can adjust the initial value of the packing factor and iterate the packing factor of the equilibrium equation again to determine whether the model can accurately predict the actual pressure of the olefin polymerization system. Here, a better initial value of the packing factor of the gas phase is 10 -10 , and a better initial value of the packing factor of the liquid phase is 0.6.

[0053] Next, the processor can calculate the fugacity coefficients of each component in both the gas and liquid phases. Specifically, the fugacity coefficient is a function of the mole fraction of the phase and the packing factor. For multi-component polymers, equipotential conditions must be ensured to satisfy phase equilibrium conservation; that is, the chemical potentials of each component in the gas and liquid phases must be equal. This chemical potential equality condition can be replaced by the fugacity equality condition. In the case of multi-component polymers, the fugacity equality condition is represented as a high-dimensional vector, and it is necessary to ensure that each term of the vector satisfies the vapor-liquid phase equilibrium condition.

[0054] Next, the processor can calculate the fugacity of each component in both the gas and liquid phases based on the aforementioned fugacity coefficients, and set the fugacity-related gas-liquid phase equilibrium conditions accordingly:

[0055] Among them, f i I f represents the fugacity of component i in the gas phase. i II Let i be the fugacity of component i in the liquid phase. Let i be the mole fraction of component i in the gas phase. Let i be the mole fraction of component i in the liquid phase. Let be the fugacity coefficient of component i in the gas phase. Let fvek be the fugacity coefficient of component i in the liquid phase, and fvek be the gas-liquid phase equilibrium condition.

[0056] Subsequently, in response to the mole fractions of each component satisfying the gas-liquid phase equilibrium condition, i.e. The processor can determine the solubility of at least one liquid component in an olefin polymerization system based on its mole fraction.

[0057] Please refer to Figure 2. Figure 2 shows a schematic flowchart of the iterative update of the molar coefficients according to some embodiments of the present invention.

[0058] As shown in Figure 2, in response to the fact that the mole fraction of each component does not meet the gas-liquid phase equilibrium condition, the processor can iteratively update the mole fraction of each liquid phase component until the mole fraction of each component meets the gas-liquid phase equilibrium condition.

[0059] Specifically, during the iterative update of the mole fraction of each liquid phase component, the processor can add perturbations to each liquid phase component to calculate the partial derivative J(g, h) of the fugacity difference between the liquid and gas phases with respect to the mole fraction of the liquid phase:

[0060] in, The mole fraction of component h added to the liquid phase to cause disturbance, where σ is a small disturbance (e.g., 10). -7 ), f IInewhJ(g, h) is the partial derivative of the fugacity difference between the liquid phase and the gas phase of component h to the liquid phase mole fraction.

[0061] Subsequently, the processor can construct a Jacobian matrix according to the set of partial derivatives of each liquid phase component:

[0062] Further, the processor can iteratively update the mole fraction of each liquid phase component according to the Jacobian matrix:

[0063] Wherein, n is the number of iterations.

[0064] In addition, in some preferred embodiments, in the process of iteratively updating the mole fraction of each liquid phase component according to the Jacobian matrix, in response to the update of the mole fraction of each liquid phase component, the processor can further perform non-negativity processing and normalization processing on each mole fraction before the next iteration:

[0065] In this way, the processor can make each mole fraction meet the non-negativity condition and the component conservation condition through the above non-negativity processing and normalization processing, so as to improve the reliability of the result.

[0066] Further, in response to the mole fraction of each component meeting the gas-liquid phase equilibrium condition, the processor can solve the solubility of at least one liquid phase component in the olefin polymerization system according to the mole fraction of the component:

[0067] Wherein, S is the sum of the mass fraction of all monomers, Sx(i) is the mass fraction of each monomer i, Sam(i) is the ratio of the mass fraction Sx(i) of monomer i to the mass fraction of the polymer, mw i is the molecular weight of component i.

[0068] In order to verify the calculation effect of the solubility calculation method provided by the first aspect of the present application, the processor can calculate the solubility of each monomer in the multi-component polymerization system under the conditions of 343.15K, 363.15K, 423.15K and 0.1-30MPa, and compare with the experimental data.

[0069] Specifically, please refer to FIG. 3-8 and Table 1-6. FIG. 3 shows the pressure-solubility curve of ethylene, propylene in isotactic polypropylene at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. FIG. 4 shows the pressure-solubility curve of ethylene, propylene in isotactic polypropylene at 363.15 K, 0.1-30 MPa according to some embodiments of the present application. FIG. 5 shows the pressure-solubility curve of ethylene, 1-hexene in LLDPE at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. FIG. 6 shows the pressure-solubility curve of ethylene, 1-hexene in LLDPE at 363.15 K, 0.1-30 MPa according to some embodiments of the present application. FIG. 7 shows the pressure-solubility curve of ethylene, 1-hexene in LLDPE at 423.15 K, 0.1-30 MPa according to some embodiments of the present application. FIG. 8 shows the pressure-solubility curve of propylene, H2 in PP at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 1 shows the solubility calculation results of ethylene, propylene in isotactic polypropylene at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 2 shows the solubility calculation results of ethylene, propylene in isotactic polypropylene at 363.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 3 shows the solubility calculation results of ethylene, 1-hexene in LLDPE at 343.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 4 shows the solubility calculation results of ethylene, 1-hexene in LLDPE at 363.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 5 shows the solubility calculation results of ethylene, 1-hexene in LLDPE at 423.15 K, 0.1-30 MPa according to some embodiments of the present application. Table 6 shows the solubility calculation results of propylene, H2 in PP at 343.15 K, 0.1-30 MPa according to some embodiments of the present application.

[0070] Table 1 Solubility calculation results of ethylene in isotactic polypropylene

[0071] Table 2 Solubility calculation results of propylene in isotactic polypropylene

[0072] Table 3 Solubility calculation results of ethylene, 1-hexene in LLDPE

[0073] Table 4 Solubility calculation results of ethylene, 1-hexene in LLDPE

[0074] Table 5 Solubility calculation results of ethylene, 1-hexene in LLDPE

[0075] Table 6 Solubility calculation results of propylene, H2 in PP

[0076] As shown in Figures 3-8 and Tables 1-6, the solubility calculation method provided by the first aspect of the present application has an average error of no more than 3.98% compared with the experimental data obtained by ASPEN.

[0077] In summary, the solubility calculation method, solubility calculation device and computer storage medium provided by the present application can add perturbations to the mole fractions of multiple components respectively, construct a multi-dimensional Jacobian partial derivative matrix, and update each component synchronously, to solve the vapor-liquid equilibrium problem of a multi-component mixture, so as to quickly and accurately converge to a phase equilibrium point.

[0078] Although the above methods are illustrated and described as a series of acts, it will be appreciated that not all of the acts are necessarily performed in the order indicated, as some acts can occur in different orders and / or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a measurement could be taken before a process is started.

[0079] Those skilled in the art will understand that the information, signals, and data can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0080] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

[0081] Although the processor described in the above embodiments can be implemented by a combination of software and hardware, it is understood that the processor can be implemented in software or hardware. For hardware implementation, the controller 40 can be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units, or a selective combination thereof implementing the functions described above. For software implementation, the processor can be implemented by separate software modules such as procedures and functions, each of which performs one or more of the functions and operations described herein.

[0082] The various illustrative logical blocks, circuits, and circuitry described in connection with the embodiments disclosed herein can be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0083] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium can be integral to the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In the alternative, the processor and the storage medium can reside as discrete components in a user terminal.

[0084] In one or more exemplary embodiments, the functions described can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functions can be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0085] The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A solubility calculation method, characterized by, The method comprises the following steps: setting initial molar fractions of a plurality of components in a gas-liquid two-phase olefin polymerization system, initial temperature, initial pressure, material parameters of each of the components, and binary interaction parameters between each of the components, wherein the sum of the initial molar fractions of each of the components in the gas-liquid two-phase is 1; calculating the fugacity of each of the components in the gas-liquid two-phase, and setting a fugacity-related gas-liquid phase equilibrium condition according to the fugacity; and in response to the molar fractions of each of the components satisfying the gas-liquid phase equilibrium condition, solving the solubility of at least one liquid-phase component in the olefin polymerization system according to the molar fraction of the liquid-phase component.

2. The solubility calculation method of claim 1, wherein, The substance parameters comprise the number of fragments m, the fragment diameter σ and / or the fragment energy ε / kb of the corresponding component, the binary interaction parameter κ ij is a function of the temperature T.

3. The solubility calculation method of claim 1, wherein, Before calculating the fugacity of each of the components in the gas-liquid two-phase, the solubility calculation method further comprises the following steps: solving the equilibrium equation that the pressure of the gas-liquid two-phase must satisfy according to the thermodynamic equilibrium condition F, using the residual Helmholtz energy model of the PC-SAFT, and iteratively updating the packing factor of the equilibrium equation to determine whether the model can accurately predict the actual pressure of the olefin polymerization system; and in response to the determination result that the model cannot accurately predict the actual pressure of the olefin polymerization system, adjusting the initial value of the packing factor and iteratively updating the packing factor of the equilibrium equation to determine whether the model can accurately predict the actual pressure of the olefin polymerization system.

4. The solubility calculation method according to claim 3, wherein, The balance equation is expressed as: P cal (η) = Zk B Tρ where F is the thermodynamic equilibrium condition, P cal is the actual pressure, P sys is the initial pressure, η is the packing factor, Z is the compressibility factor, k B is the Boltzmann constant, T is the temperature, and p is the molecular density, The step of iterating the build-up factor to the balance equation is denoted as: wherein n is the number of iterations, and F' is the first-order derivative of F with respect to η.

5. The solubility calculation method of claim 1, wherein, The step of calculating the fugacity of each of the components in the gas and liquid phases and setting the fugacity-dependent gas-liquid equilibrium conditions accordingly is denoted as: wherein the fugacity of component i in the gas phase, the fugacity of component i in the liquid phase, mole fraction of component i in the gas phase, the molar fraction of component i in the liquid phase, the fugacity coefficient of component i in the gas phase, is the fugacity coefficient of component i in the liquid phase, and fvek is the gas-liquid phase equilibrium condition.

6. The solubility calculation method of claim 1, wherein, The method further comprises the following steps: in response to the molar fractions of each of the components not satisfying the gas-liquid phase equilibrium condition, iteratively updating the molar fractions of each of the liquid-phase components until the molar fractions of each of the components satisfy the gas-liquid phase equilibrium condition.

7. The solubility calculation method of claim 6, wherein, The step of iteratively updating the molar fractions of each of the liquid-phase components comprises: A perturbation is added to each of the liquid phase components to calculate the partial derivative of the difference in fugacity between the liquid and gas phases with respect to the liquid phase mole fraction, J(g, h), for each of the liquid phase components: wherein where σ is a small perturbation, f is the mole fraction of the perturbed component h in the liquid phase IInewh where σ is a small perturbation, f is the mole fraction of the perturbed component h in the liquid phase A Jacobian matrix is constructed from a set of partial derivatives of each of the liquid phase components, and the molar fractions of each of the liquid phase components are iteratively updated according to the Jacobian matrix: wherein n is the number of iterations.

8. The solubility calculation method of claim 7, wherein, In the process of iteratively updating the molar fractions of each of the liquid-phase components according to the Jacobian matrix, the solubility calculation method further comprises the following steps: In response to the update of the molar fraction of each of the liquid-phase components, each of the molar fractions is first subjected to non-negativity processing and normalization processing, and then subjected to the next round of iteration:

9. The solubility calculation method of claim 1, wherein, The step of solving the solubility of at least one liquid component in the olefin polymerization system according to its molar fraction is expressed as: where S is the sum of the mass fractions of all monomers, Sx(i) is the mass fraction of each monomer i, Sam(i) is the ratio of the mass fraction Sx(i) of monomer i to the mass fraction of the polymer, mw i is the molecular weight of component i.

10. A solubility calculation device, characterized by, comprising: a memory having computer instructions stored thereon; and a processor connected to the memory and configured to execute the computer instructions stored on the memory to implement the solubility calculation method of any one of claims 1-9.

11. A computer readable storage medium having stored thereon computer instructions, wherein, The computer instructions are executed by the processor to implement the solubility calculation method of any one of claims 1-9. The computer instructions are executed by the processor to implement the solubility calculation method of any one of claims 1-9.

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