A method for calculating the fugacity coefficient and correcting the gas phase partial pressure of components based on the SRK equation

Abstract

The present invention discloses a method for calculating the fugacity coefficient based on the SRK equation and correcting the gas phase partial pressure of the components, so as to obtain a more accurate relationship between the gas-liquid phase composition of the components. This method can avoid the problem that the gas-liquid phase equilibrium relationship obtained by the traditional method is too ideal and cannot accurately express the relationship between the gas-liquid phase composition in actual production. The method is to obtain the required mixture parameters through the mixing rule, and then combine the obtained mixture parameters and the SRK equation in the form of a compression factor to obtain the fugacity coefficient. The ideal gas phase partial pressure calculated by the Antoine equation is corrected by the fugacity coefficient, and then the mixture fugacity is obtained by using the corrected gas phase partial pressure of each component and used to replace the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally a relatively true relationship between the gas-liquid phase composition can be obtained.

Description

Technical Field

[0001] The present application relates to the technical field of simulation modeling, and in particular to a method for calculating the fugacity coefficient based on the SRK equation and correcting the gas phase partial pressure of a component. Background Art

[0002] In recent years, my country's chemical industry has flourished. The flash evaporation system with flash tank as the core has always played an extremely important role in the chemical production process. It is widely used in the petroleum industry, chemical engineering, food processing, etc. In order to accurately simulate and optimize the performance of flash tanks and flash evaporation systems, researchers usually need to have a deep understanding of the thermodynamic properties and dynamic behavior of liquid phase change processes.

[0003] There are many complex and coupled calculations involved in the flash tank, among which the relationship between the gas phase composition and the liquid phase composition of a component when the vapor-liquid phase equilibrium state is reached is particularly prominent. The commonly used calculation method is to calculate the saturated vapor pressure of the component through the Antoine equation, and then further calculate the corresponding phase equilibrium constant, and finally obtain the relationship between the gas and liquid phase compositions of the component. However, the relationship obtained by this method is an ideal relationship, which cannot accurately express the relationship between the gas and liquid phase compositions in actual production. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a method for calculating the fugacity coefficient based on the SRK equation and correcting the gas phase partial pressure of the components, so as to solve the technical problem existing in the related art that it is impossible to accurately express the relationship between the gas-liquid phase composition in actual production.

[0005] According to a first aspect of an embodiment of the present application, a method for calculating a fugacity coefficient based on an SRK equation is provided, characterized by comprising:

[0006] S11: according to the vdW mixing rule, obtaining a first mixing parameter and a second mixing parameter of the liquid phase mixture;

[0007] S12: solving the SRK equation in the form of a compression factor using the first mixing parameter and the second mixing parameter to obtain a plurality of solutions;

[0008] S13: Selecting a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and the solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; wherein Tr is the component contrast temperature;

[0009] S4: Calculate the fugacity coefficient using the first mixing parameter, the second mixing parameter and a solution that meets the requirements.

[0010] According to a second aspect of an embodiment of the present application, a device for calculating a fugacity coefficient based on an SRK equation is provided, characterized in that it includes:

[0011] A first solving module is used to obtain a first mixing parameter and a second mixing parameter of the liquid phase mixture according to a vdW mixing rule;

[0012] A second solving module is used to solve the SRK equation in a compression factor form by using the first mixing parameter and the second mixing parameter to obtain multiple solutions;

[0013] A selection module is used to select a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and the solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; Tr is the component contrast temperature;

[0014] The third solution module is used to obtain the fugacity coefficient by using the first mixing parameter, the second mixing parameter and a solution that meets the requirements.

[0015] According to a third aspect of an embodiment of the present application, a method for correcting a component gas phase partial pressure is provided, comprising:

[0016] S21: Execute the method for calculating the fugacity coefficient based on the SRK equation described in the first aspect to obtain the fugacity coefficient;

[0017] S22: According to the fugacity coefficient, the corrected gas phase partial pressure of each component is obtained, and the mixture fugacity f is calculated from the corrected gas phase partial pressure m ;

[0018] S23: Calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m By replacing the total pressure P in the traditional gas-liquid phase equilibrium equation, a more accurate expression of the gas-liquid phase composition relationship is finally obtained.

[0019] According to a fourth aspect of an embodiment of the present application, there is provided a device for correcting a component gas phase partial pressure, comprising:

[0020] An execution module, used to execute the method for calculating the fugacity coefficient based on the SRK equation described in the first aspect to obtain the fugacity coefficient;

[0021] The fourth solution module is used to obtain the corrected gas phase partial pressure of each component according to the fugacity coefficient, and to calculate the mixture fugacity f from the corrected gas phase partial pressure. m ;

[0022] The fifth solution module is used to calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m By replacing the total pressure P in the traditional gas-liquid phase equilibrium equation, a more accurate expression of the gas-liquid phase composition relationship is finally obtained.

[0023] According to a fifth aspect of an embodiment of the present application, there is provided an electronic device, including:

[0024] one or more processors;

[0025] A memory for storing one or more programs;

[0026] When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in the first aspect or the third aspect.

[0027] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0028] It can be seen from the above embodiments that the present application obtains the required mixture parameters through the mixing rule, and then combines the obtained mixture parameters and the SRK equation in the form of a compression factor to obtain the fugacity coefficient, and then uses the fugacity coefficient to correct the ideal gas phase partial pressure calculated by the Antoine equation, and finally obtains a relatively true relationship between the gas-liquid phase composition, which can avoid the gas-liquid phase equilibrium relationship obtained by the traditional method being too ideal and unable to accurately express the relationship between the gas-liquid phase composition in actual production.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0031] Figure 1 The figure is a flow chart showing a method for calculating the fugacity coefficient based on the SRK equation according to an exemplary embodiment.

[0032] Figure 2 The invention is a block diagram of a device for calculating the fugacity coefficient based on the SRK equation according to an exemplary embodiment.

[0033] Figure 3 The figure is a flow chart showing a method for correcting the gas phase partial pressure of a component according to an exemplary embodiment.

[0034] Figure 4 is returned by a function according to an exemplary embodiment The process of value change.

[0035] Figure 5 According to an exemplary embodiment, the use The changing trends of y and x when the system reaches the gas-liquid equilibrium state before and after correction.

[0036] Figure 6 It is a block diagram of a device for correcting gas phase partial pressure of a component according to an exemplary embodiment. DETAILED DESCRIPTION

[0037] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0038] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0039] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0040] Figure 1 is a flow chart showing a method for calculating the fugacity coefficient based on the SRK equation according to an exemplary embodiment. Figure 1 As shown, the method may include the following steps:

[0041] S11: According to the vdW (van der Waals) mixing rule, the first mixing parameter and the second mixing parameter of the liquid phase mixture are obtained; in order to obtain the first mixing parameter Am and the second mixing parameter Bm of the liquid phase mixture in step S1, it is necessary to obtain the dimensionless quantities Ai and Bi corresponding to each pure component, and in order to obtain the Ai and Bi, it is necessary to obtain the pressure correction term ai and the volume correction term bi corresponding to each pure component. This step may include the following sub-steps:

[0042] S111: Calculate the pressure correction term ai and volume correction term bi corresponding to each pure component by the following formula;

[0043]

[0044]

[0045] In the above formula, R is a constant (8.314), p is the total pressure of the system, T is the system temperature, Tc, Pc, and w are the inherent properties of different components, namely, critical temperature, critical pressure, and eccentricity factor;

[0046] Specifically, this embodiment is to separate a binary mixture of benzene and toluene. In this step, the specific physical parameters Tc, Pc, and w of the two are substituted into the above expression to obtain the pressure correction term a1 and volume correction term b1 of benzene; and the pressure correction term a2 and volume correction term b2 of toluene.

[0047] S112: Based on ai and bi, the pressure correction term am, volume correction term bm and dimensionless quantities Ai and Bi corresponding to each pure component of the mixture are calculated by the following formula;

[0048]

[0049]

[0050] A i =a i p / (R 2 T 2 ) (5)

[0051] B i =b i p / (RT) (6)

[0052] Where yi is the gas phase molar composition of each component;

[0053] Specifically, according to the above-obtained a1, b1; a2, b2 and the gas phase molar composition of benzene y1, the gas phase molar composition of toluene y2 are substituted into the above expression to obtain the pressure correction term am and volume correction term bm of the mixture, as well as the dimensionless quantities A1, B1 corresponding to benzene and A2, B2 corresponding to toluene.

[0054] S113: According to Ai and Bi, the first mixing parameter Am and the second mixing parameter Bm of the mixture are calculated by the following formula;

[0055]

[0056]

[0057] Substituting the Tc, Pc, and w corresponding to different components into equations (1) and (2) can obtain the corresponding a i ,b i ; further obtain a i ,b i , and other required parameters are brought into equations (5) and (6) to obtain the corresponding A i ,B i ,; further A i ,B i , and other required parameters are substituted into equations (7) and (8) to obtain the corresponding Am, Bm. Thus, the first mixing parameter Am and the second mixing parameter Bm are obtained according to the vdW mixing rule.

[0058] Specifically, the first mixture parameter Am and the second mixture parameter Bm of the benzene-toluene binary mixture can be obtained by substituting the above-obtained A1, B1, A2, and B2 into the above-mentioned expressions.

[0059] Since the relationship between the gas-liquid phase composition y and x of a component in the mixture is ultimately required, a mixture model different from the pure component must first be constructed. The above expressions can be used to obtain various important parameters related to the mixture, and these key mixture parameters can be used to represent the mixture model in this embodiment, namely the benzene-toluene binary mixture model. Constructing a more realistic mixture model plays a vital role in the advancement of subsequent algorithm processes.

[0060] S12: solving the SRK (Soave-Redlich-Kwong equation of state) in the form of a compression factor using the first mixing parameter and the second mixing parameter to obtain multiple solutions;

[0061] Specifically, the SRK equation expression in the form of the compression factor is as follows:

[0062]

[0063] Where z is the compression factor, Am and Bm are the first mixing parameter and the second mixing parameter respectively.

[0064] Since the original form of the SRK equation is difficult to solve, the SRK equation in the form of a compression factor is used instead, as shown in equation (9).

[0065] S13: Select a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and this solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; wherein Tr is the component contrast temperature.

[0066] Specifically, according to the meaning of the solutions to the state equation, the largest solution corresponds to the gas phase, the smallest solution corresponds to the liquid phase, and the solution in the middle has no physical meaning. It is used here to correct the gas phase partial pressure of the components, so the largest solution is taken.

[0067] The pressure that needs to be corrected in this embodiment is the gas phase partial pressure of each component, and the comparative temperature Tr in this embodiment is less than 1, so the largest solution is found among the three solutions of formula (9) for subsequent calculations.

[0068] S14: Calculate the fugacity coefficient using the first mixing parameter, the second mixing parameter and a solution that meets the requirements.

[0069] Specifically, the mixture is mixed according to the vdW mixing rule, and the fugacity coefficient of component i in the mixture is derived from the SRK equation: The expression is as follows:

[0070]

[0071] Wherein bi is the volume correction term corresponding to each pure component; am is the pressure correction term corresponding to the mixture; bm is the volume correction term corresponding to the mixture; Am and Bm are the first mixing parameter and the second mixing parameter respectively; z is the compression factor; bi, am, bm, Am, Bm, and z are all obtained through the above steps.

[0072] Specifically, the above-obtained results of the benzene-toluene binary mixture are substituted into equation (10) to obtain the fugacity coefficient corresponding to benzene: And the fugacity coefficient corresponding to toluene

[0073] To obtain the mixture fugacity f m , then it is necessary to find the fugacity corresponding to each component, and thus it is necessary to find the fugacity coefficient corresponding to each component in the mixture according to expression (10).

[0074] Corresponding to the aforementioned embodiment of the method for calculating the fugacity coefficient based on the SRK equation, the present application also provides an embodiment of a device for calculating the fugacity coefficient based on the SRK equation.

[0075] Figure 2 is a block diagram of a device for calculating the fugacity coefficient based on the SRK equation according to an exemplary embodiment. Figure 2 , the device comprises:

[0076] A first solving module 11 is used to obtain a first mixing parameter and a second mixing parameter of the liquid phase mixture according to a vdW mixing rule;

[0077] A second solving module 12 is used to solve the SRK equation in the form of a compression factor using the first mixing parameter and the second mixing parameter to obtain multiple solutions;

[0078] The selection module 13 is used to select a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and the solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; Tr is the component contrast temperature;

[0079] The third solution module 14 is used to obtain the fugacity coefficient by using the first mixing parameter, the second mixing parameter and a solution that meets the requirements.

[0080] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0081] Figure 3 is a flow chart showing a method for correcting the gas phase partial pressure of a component according to an exemplary embodiment. Figure 3 As shown, the method may include the following steps:

[0082] S21: Execute the above method for calculating the fugacity coefficient based on the SRK equation to obtain the fugacity coefficient;

[0083] This step has been described in detail above and will not be repeated here.

[0084] S22: According to the fugacity coefficient, the corrected gas phase partial pressure of each component is obtained, and the mixture fugacity f is calculated from the corrected gas phase partial pressure m ; This step may include the following sub-steps:

[0085] S221: Using the fugacity coefficient, obtain the corrected gas phase partial pressure f of each component i , f i The expression is as follows:

[0086]

[0087] Specifically, in this embodiment, the fugacity coefficient corresponding to benzene obtained above is used And the molar composition of benzene y1 can be used to calculate the gas phase partial pressure f1 corresponding to the corrected benzene; similarly, the gas phase partial pressure f2 corresponding to toluene can be obtained.

[0088] S222: Using the gas phase partial pressure f of each component i , and the mixture fugacity f is obtained m The expression is as follows:

[0089]

[0090] In formula (11)-(12), yi is the gas phase molar fraction of the corresponding component, and n in formula (12) represents the number of components in the mixture system.

[0091] Specifically, in this embodiment, since it is a benzene-toluene binary mixture, n is 2. Therefore, the above-obtained f1, f2 and the molar compositions of benzene and toluene y1, y2 are substituted into formula (12) to obtain the fugacity f corresponding to the mixture, i.e., the entire system. m .

[0092] From this, the mixture fugacity f can be obtained m , so as to obtain the mixture fugacity f m Compared with the traditional method of using the gas phase composition yi of each component and its corresponding fugacity f i It is more scientific to multiply and then add, and it also makes the result more scientific and closer to the actual mixed gas.

[0093] S23: Calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m Replacing the total pressure P in the traditional gas-liquid phase equilibrium equation, a more accurate expression of the gas-liquid phase composition relationship is finally obtained. This step may include the following sub-steps:

[0094] S231: The expression for calculating the saturated vapor pressure of a component according to the Antoine equation is as follows:

[0095] ln(Pb0)=α-β / (T+γ) (13)

[0096] In the formula, α, β, and γ are all physical constants, and different substances have different values. T is the system temperature;

[0097] Specifically, since we need to obtain the gas phase molar composition y1 (represented by y here) and the liquid phase molar composition x1 (represented by x here) of the light component benzene in the binary mixture, it is necessary to substitute the physical property constants α, β, and γ corresponding to benzene into the above expression to calculate the saturated vapor pressure (Pb0) of benzene.

[0098] S232: Using the mixture fugacity f m It replaces the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally obtains a more accurate expression of the gas-liquid phase composition relationship;

[0099] The relationship before correction is:

[0100] y*P=Pb0*x (14)

[0101] The corrected relationship is:

[0102] y*f m =Pb0*x (15)

[0103] Where x and y are the liquid and gas phase molar fractions of the components, respectively, P is the total system pressure, Pb0 is the saturated vapor pressure of the component, and f m is the fugacity of the mixture.

[0104] Therefore, the fugacity f corresponding to the mixture, that is, the entire system, is m , and the Pb0 corresponding to benzene is substituted into formula (15) to obtain a more accurate and closer to the actual state of the relationship between the gas phase molar composition y of benzene and its liquid phase molar composition x when the gas-liquid equilibrium is reached.

[0105] The above method of obtaining the relationship between the gas-liquid phase composition of a component in the mixture at gas-liquid equilibrium effectively improves the result obtained by formula (14). Specifically, fugacity represents the effective pressure of the actual gas in chemical thermodynamics, and its definition starts from the relationship between the chemical potential and the pressure of the ideal gas. In relevant chemical calculations, fugacity can be used as the pressure of the actual gas to replace the true pressure P for subsequent calculations, thereby avoiding the deviation of the calculation results from the actual due to the difference between the ideal gas and the actual gas. This algorithm flow is used in this example, and the fugacity coefficient of each component is obtained by combining the vdW mixing rule with the SRK equation, and then the mixture fugacity f corresponding to the mixture is obtained based on the fugacity coefficient. m , and replace it with the actual pressure P to finally obtain a relationship between the gas and liquid phase compositions of the components that is closer to the actual situation.

[0106] Specifically, the components in the flash tank continuously undergo mass transfer and heat transfer between the gas and liquid phases until the entire system reaches a vapor-liquid equilibrium state. When the system reaches a vapor-liquid equilibrium state, the relationship between the gas phase composition y and the liquid phase composition x of the same component (taking the light component in the binary mixture mentioned above as an example) can be expressed by the following phase equilibrium equation:

[0107] y=kb*x (16)

[0108] Where kb is the phase equilibrium constant.

[0109] The commonly used calculation method is to calculate the saturated vapor pressure Pb0 of the component through the Antoine equation, and then divide it by the total pressure P of the system to obtain the following equation:

[0110] ln(Pb0)=α-β / (T+γ) (13)

[0111] kb=Pb0 / P (17)

[0112] Where α, β, and γ are all physical constants. Different substances have different values ​​(which can be directly obtained from relevant materials). T is the system temperature and P is the total pressure of the system.

[0113] Therefore, the relationship between the gas phase composition y and the liquid phase composition x of the light component in the phase equilibrium state is determined. From (16) and (17), the following equation can be obtained:

[0114] y*P=Pb0*x (14)

[0115] However, the equation (14) is the relationship between the gas-liquid phase composition of a certain component under ideal conditions, which cannot accurately express the relationship between the gas-liquid phase composition in actual production. Therefore, the mixture fugacity f obtained above is used m Substituting the total system pressure P to correct the relationship between the gas and liquid phase compositions, the corrected expression is as follows:

[0116] y*f m =Pb0*x (15)

[0117] Where x and y are the liquid and gas phase molar fractions of the components, respectively, P is the total pressure of the system, Pb0 is the saturated vapor pressure of the component, and f m is the fugacity of the mixture.

[0118] The method of the present application is implemented by programming using the physical system modeling language Modelica. Due to the wide application of this language in the modeling field, the method also has good scalability.

[0119] Modelica language has a profound influence in the field of simulation modeling technology and is used more and more widely due to its object-oriented and scalable features. In particular, its equation-driven modeling approach allows users to directly describe system behavior in the form of equations, which is more suitable for the modeling needs of natural systems and improves readability and operability.

[0120] All the above formulas are implemented based on Modelica language, and all the formulas are integrated and encapsulated in a Modelica-based function according to their inherent causal logic and sequence. The function implements the function of inputting system temperature T, system pressure P, binary mixture light component gas phase molar fraction y, binary mixture light component liquid phase molar fraction x, and finally outputs the fugacity coefficients of two different components through complex and coupled calculations and the screening algorithm of equation solutions. Thus, the relationship between y and x is corrected. Meanwhile, the flash tank is also a flash tank model constructed based on Modelica language.

[0121] Figure 4 Shows the function returns The values ​​change process and finally stabilize at around 0.965 and 0.966 respectively. Figure 5 This is an example of the present application implemented based on Modelica and applied to the flash tank for the flash evaporation process of a binary mixture. This figure shows the flash evaporation process of a binary mixture using The changing trends of y and x when the system reaches the gas-liquid equilibrium state before and after correction.

[0122] It can be seen from the above embodiments that the present application obtains the fugacity coefficient The ideal gas phase partial pressure is corrected, and a relatively realistic relationship between the gas-liquid phase composition is obtained, overcoming the drawback that the gas-liquid phase equilibrium relationship obtained by the traditional method is too ideal and cannot accurately express the relationship between the gas-liquid phase composition in actual production. At the same time, this method uses the physical system modeling language Modelica for programming. Due to the wide application of this language in the modeling field, this method also has good scalability. In addition, the effectiveness of the above algorithm has been verified through simulation, providing chemical engineering technicians with a new way to obtain a more accurate relationship between the gas-liquid phase composition when the gas-liquid phase equilibrium is reached during the separation of binary mixtures.

[0123] Corresponding to the aforementioned embodiment of the method for correcting the gas phase partial pressure of a component, the present application also provides an embodiment of an apparatus for correcting the gas phase partial pressure of a component.

[0124] Figure 6 is a block diagram of a device for correcting the gas phase partial pressure of a component according to an exemplary embodiment. Figure 6 , the device comprises:

[0125] An execution module 21 is used to execute the above-mentioned method for calculating the fugacity coefficient based on the SRK equation to obtain the fugacity coefficient;

[0126] The fourth solution module 22 is used to obtain the corrected gas phase partial pressure of each component according to the fugacity coefficient, and calculate the mixture fugacity f from the corrected gas phase partial pressure. m ;

[0127] The fifth solution module 23 is used to calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m By replacing the total pressure P in the traditional gas-liquid phase equilibrium equation, a more accurate expression of the gas-liquid phase composition relationship is finally obtained.

[0128] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0129] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, 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 present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0130] Correspondingly, the present application also provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the method for calculating the fugacity coefficient based on the SRK equation or the method for correcting the gas phase partial pressure of a component as described above.

[0131] Accordingly, the present application also provides a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the method for calculating the fugacity coefficient based on the SRK equation or the method for correcting the gas phase partial pressure of a component as described above.

[0132] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0133] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for correcting the gas phase partial pressure of a component, characterized in that: include: S21: Execute the method for calculating the fugacity coefficient based on the SRK equation to obtain the fugacity coefficient; S22: According to the fugacity coefficient, the corrected gas phase partial pressure of each component is obtained, and the mixture fugacity f is calculated from the corrected gas phase partial pressure m ; S23: Calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m It replaces the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally obtains a more accurate expression of the gas-liquid phase composition relationship; The method for calculating the fugacity coefficient based on the SRK equation includes: S11: according to the vdW mixing rule, obtaining a first mixing parameter and a second mixing parameter of the liquid phase mixture; S12: solving the SRK equation in the form of a compression factor using the first mixing parameter and the second mixing parameter to obtain a plurality of solutions; S13: Selecting a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and the solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; wherein Tr is the component contrast temperature; S14: Calculating the fugacity coefficient using the first mixing parameter, the second mixing parameter and a solution that meets the requirements; S23 includes the following sub-steps: S231: The expression for calculating the saturated vapor pressure of a component according to the Antoine equation is as follows: ln(Pb0)=α-β / (T+γ) In the formula, α, β, and γ are all physical constants, and different substances have different values. T is the system temperature; S232: Using the mixture fugacity f m It replaces the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally obtains a more accurate expression of the gas-liquid phase composition relationship; The relationship before correction is: y*P=Pb0*x The corrected relationship is: y*f m =Pb0*x Where x and y are the liquid and gas phase molar fractions of the components, respectively, P is the total pressure of the system, Pb0 is the saturated vapor pressure of the component, and f m is the fugacity of the mixture.

2. The method according to claim 1, characterized in that: S11 includes the following sub-steps: S111: Calculate the pressure correction term ai and volume correction term bi corresponding to each pure component by the following formula; In the above formula, R is a constant, p is the total pressure of the system, T is the system temperature, Tc, Pc, and w are the inherent properties of different components, namely, critical temperature, critical pressure, and eccentricity factor; S112: Based on ai and bi, the pressure correction term am, volume correction term bm and dimensionless quantities Ai and Bi corresponding to each pure component of the mixture are calculated by the following formula; A i =a i p / (R 2 T 2 ) B i =b i p / (R 2 T 2 ) Where yi is the gas phase molar composition of each component; S113: According to Ai and Bi, the first mixing parameter Am and the second mixing parameter B of the mixture are calculated by the following formula: m ; 3. The method according to claim 1, characterized in that The SRK equation expression in the form of the compression factor is as follows: Where z is the compression factor, Am and Bm are the first mixing parameter and the second mixing parameter respectively.

4. The method according to claim 1, characterized in that: The fugacity coefficient Solve the equation as follows: Where bi is the volume correction term corresponding to each pure component; am is the pressure correction term corresponding to the mixture; bm is the volume correction term corresponding to the mixture; Am and Bm are the first mixing parameter and the second mixing parameter respectively; z is the compressibility factor.

5. The method according to claim 1, characterized in that S22 includes the following sub-steps: S221: Using the fugacity coefficient, obtain the corrected gas phase partial pressure f of each component i , f i The expression is as follows: S222: Using the gas phase partial pressure f of each component i , and the mixture fugacity f is obtained m The expression is as follows: In the formula, is the fugacity coefficient, yi is the gas phase molar fraction of the corresponding component, and n represents the number of components in the mixture system.

6. A device for correcting the gas phase partial pressure of a component, characterized in that: include: An execution module, used for executing a method for calculating the fugacity coefficient based on the SRK equation to obtain the fugacity coefficient; The fourth solution module is used to obtain the corrected gas phase partial pressure of each component according to the fugacity coefficient, and to calculate the mixture fugacity f from the corrected gas phase partial pressure. m ; The fifth solution module is used to calculate the saturated vapor pressure Pb0 of the component using the Antoine equation, and then use the mixture fugacity f m It replaces the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally obtains a more accurate expression of the gas-liquid phase composition relationship; The method for calculating the fugacity coefficient based on the SRK equation includes: S11: according to the vdW mixing rule, obtaining a first mixing parameter and a second mixing parameter of the liquid phase mixture; S12: solving the SRK equation in the form of a compression factor using the first mixing parameter and the second mixing parameter to obtain a plurality of solutions; S13: Selecting a solution that meets the requirements from the multiple solutions, specifically: if Tr is greater than 1, the SRK equation has only one real number solution, and the solution is taken as the solution that meets the requirements; if Tr is less than 1, the SRK equation has three real number solutions, and the largest solution is selected as the solution that meets the requirements; wherein Tr is the component contrast temperature; S14: Calculating the fugacity coefficient using the first mixing parameter, the second mixing parameter and a solution that meets the requirements; S23 includes the following sub-steps: S231: The expression for calculating the saturated vapor pressure of a component according to the Antoine equation is as follows: ln(Pb0)=α-β / (T+γ) In the formula, α, β, and γ are all physical constants, and different substances have different values. T is the system temperature; S232: Using the mixture fugacity f m It replaces the total pressure P in the traditional gas-liquid phase equilibrium equation, and finally obtains a more accurate expression of the gas-liquid phase composition relationship; The relationship before correction is: y*P=Pb0*x The corrected relationship is: y*f m =Pb0*x Where x and y are the liquid and gas phase molar fractions of the components, respectively, P is the total pressure of the system, Pb0 is the saturated vapor pressure of the component, and f m is the fugacity of the mixture.

7. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 5.

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