Chemical purification method, device, equipment and medium for vapor-liquid flash evaporation with nested inner and outer layers

Abstract

The invention discloses a chemical purification method, device, equipment and medium for inner and outer layer nested vapor-liquid flash evaporation, and relates to the technical field of chemical engineering and industrial computation.The chemical purification method comprises the steps that according to compound parameters of a chemical mixture, a temperature initial value and a vapor phase fraction initial value are calculated, and equilibrium constants of corresponding components at different temperatures are calculated; calculating a vapor-phase component and a liquid-phase component based on the initial temperature value, the initial vapor-phase fraction value and the equilibrium constant of each component; judging whether a vapor-liquid flash evaporation inner layer of the chemical mixture converges or not, and if yes, performing deviation calculation on a vapor-phase component and a liquid-phase component to obtain a deviation value; whether the deviation value is smaller than a preset specific tolerance or not is judged, if yes, inner layer circulation is ended, and enthalpies at the current temperature, the current component and the current vapor phase fraction are calculated; whether the enthalpy is smaller than a preset enthalpy value or not is judged, if not, outer layer circulation is ended, and chemical purification of inner and outer layer nested vapor-liquid flash evaporation is completed, inner and outer layer nested vapor-liquid flash evaporation calculation can be achieved, and the chemical purification quality and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering and industrial computing technology, and in particular to a chemical purification method, device, equipment and medium for inner and outer layer nested vapor-liquid flash evaporation. Background Art

[0002] In the chemical and oil refining production processes, it is necessary to purify compounds, such as separating gasoline, diesel and asphalt from petroleum. Different compounds have different volatility, which can be roughly understood as the ease with which liquid compounds vaporize, such as gasoline is more volatile than diesel at the same temperature. When a liquid mixture of multiple compounds is injected into a tank with a specific pressure and temperature, part of it will vaporize into a gas, containing more volatile components; the rest will remain in liquid form, containing more non-volatile components. After multiple stages of operation, the purification operation of the components can be achieved. This process is called flash operation. The existing traditional flash algorithm achieves computational convergence by iterating temperature, vapor phase fraction, etc. Each iteration requires a strict calculation of equilibrium constants and enthalpy, resulting in excessive load on computer memory and processors. At the same time, due to the serious nonlinearity of the strict mechanism model, the calculation process will show serious divergence, causing the calculation results to oscillate and collapse.

[0003] As can be seen from the above, how to realize the inner and outer nested vapor-liquid flash calculation and improve the quality and efficiency of chemical purification is a problem to be solved in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a chemical purification method, device, equipment and medium for inner and outer nested vapor-liquid flash evaporation, which can realize inner and outer nested vapor-liquid flash evaporation calculation and improve the quality and efficiency of chemical purification. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a chemical purification method of inner and outer nested vapor-liquid flash evaporation, comprising:

[0006] Calculate the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture, and calculate the equilibrium constants of each component at different temperatures;

[0007] Calculate vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value, and the equilibrium constants of each component;

[0008] Using the vapor phase component and the liquid phase component to determine whether the vapor-liquid flash inner layer of the chemical mixture converges, if the vapor-liquid flash inner layer of the chemical mixture converges, then performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount;

[0009] Determine whether the deviation is less than a preset specific tolerance, if the deviation is less than the preset specific tolerance, end the inner loop, determine the current temperature, the current component and the current vapor phase fraction, and calculate the enthalpy at the current temperature, the current component and the current vapor phase fraction;

[0010] It is determined whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, the outer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

[0011] Optionally, the calculating of the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture includes:

[0012] The mixture components, compound boiling point and operating pressure in the compound parameters are calculated using the preset temperature calculation formula and vapor phase fraction calculation formula to obtain the initial temperature value and the initial vapor phase fraction value; the temperature calculation formula is:

[0013] ;

[0014] Where P is the current operating pressure, N is the number of mixture components, is the boiling point of the ith component, is the feed composition of the i-th component, T is the initial temperature;

[0015] The vapor phase fraction calculation formula is:

[0016] ;

[0017] in, is the initial value of vapor phase fraction.

[0018] Optionally, respectively calculating the equilibrium constants of the components at different temperatures includes:

[0019] Calculate the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to any two temperatures, and perform linear fitting on the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to two different temperatures to construct an equation correlation between enthalpy-equilibrium constant-temperature;

[0020] The equation correlation formula is used to calculate the equilibrium constants of each component at all different temperatures.

[0021] Optionally, the calculating of vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component comprises:

[0022] Construct equilibrium constant and enthalpy models according to preset model building rules;

[0023] The initial value of temperature, the initial value of vapor phase fraction and the equilibrium constant of each component are input into the equilibrium constant and enthalpy model for calculation to obtain vapor phase component and liquid phase component.

[0024] Optionally, the calculation formulas for the vapor phase component and the liquid phase component are:

[0025] ;

[0026] ;

[0027] in, and are the vapor phase component and liquid phase component of the i-th component in the vapor phase, is the feed composition of the ith component, is the equilibrium constant of the ith component at the current temperature T, is the initial value of vapor phase fraction.

[0028] Optionally, the performing deviation calculation on the vapor phase component and the liquid phase component includes:

[0029] The deviation calculation formula is used to calculate the deviation of the vapor phase component and the liquid phase component; the deviation calculation formula is:

[0030] ;

[0031] in, is the deviation, and N is the number of mixture components.

[0032] Optionally, after determining whether the deviation is less than a preset specific tolerance, the method further includes:

[0033] If the deviation is not less than a preset specific tolerance, the approximate derivative of the deviation with temperature is calculated;

[0034] Calculating a new vapor phase fraction using the approximate derivative, the deviation, and the initial value of the vapor phase fraction, and calculating a new temperature according to the new vapor phase fraction;

[0035] Based on the new vapor phase fraction, the new temperature and the equilibrium constants of the components, the process of calculating new vapor phase components and new liquid phase components is repeatedly performed until the deviation is smaller than a preset specific tolerance.

[0036] In a second aspect, the present application discloses a chemical purification device with inner and outer nested vapor-liquid flash evaporation, comprising:

[0037] The initial value and equilibrium constant calculation module is used to calculate the initial value of temperature and the initial value of vapor phase fraction according to the compound parameters of the chemical mixture, and calculate the equilibrium constants of each component at different temperatures;

[0038] A component calculation module, used for calculating vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component;

[0039] a deviation calculation module, for determining whether the vapor-liquid flash inner layer of the chemical mixture converges by using the vapor phase component and the liquid phase component; if the vapor-liquid flash inner layer of the chemical mixture converges, performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount;

[0040] An inner loop termination module, used for judging whether the deviation is less than a preset specific tolerance, and if the deviation is less than the preset specific tolerance, terminating the inner loop, determining the current temperature, the current component and the current vapor phase fraction, and calculating the enthalpy at the current temperature, the current component and the current vapor phase fraction;

[0041] The outer cycle termination module is used to determine whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, the outer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

[0042] In a third aspect, the present application discloses an electronic device, comprising:

[0043] Memory, used to store computer programs;

[0044] A processor is used to execute the computer program to implement the aforementioned chemical purification method of inner and outer nested vapor-liquid flash evaporation.

[0045] In a fourth aspect, the present application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the chemical purification method of inner and outer nested vapor-liquid flash evaporation disclosed above are implemented.

[0046] It can be seen that the present application provides a chemical purification method with inner and outer nested vapor-liquid flash evaporation, including calculating the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture, and calculating the equilibrium constants of the corresponding components at different temperatures respectively; calculating the vapor phase component and the liquid phase component based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constants of each component; using the vapor phase component and the liquid phase component to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, if the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, then performing deviation calculation on the vapor phase component and the liquid phase component to obtain the deviation amount; determining whether the deviation amount is less than a preset specific tolerance, if the deviation amount is less than the preset specific tolerance, then terminating the inner layer cycle, and determining the current temperature, current component and current vapor phase fraction, and calculating the enthalpy at the current temperature, the current component and the current vapor phase fraction; determining whether the enthalpy is less than a preset enthalpy value, if the enthalpy is not less than the preset enthalpy value, then terminating the outer layer cycle to complete the chemical purification with inner and outer nested vapor-liquid flash evaporation. The present application proposes an algorithm for nested vapor-liquid flash evaporation in inner and outer layers to realize chemical engineering. The initial temperature value and the initial vapor phase fraction value are calculated according to the compound parameters, and the equilibrium constants of the corresponding components at different temperatures are calculated, thereby obtaining the vapor phase components and the liquid phase components to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges. If it converges, return to the outer nesting and calculate the deviation. If the deviation is less than the preset specific tolerance, calculate the enthalpy at the current temperature, current component and current vapor phase fraction. If the enthalpy is not less than the preset enthalpy value, end the outer cycle, realize the calculation of the inner and outer nested vapor-liquid flash evaporation, complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation, improve the calculation speed and the stability of convergence, avoid the repeated iteration of temperature in the traditional model, greatly reduce the number of convergence iterations, and improve the quality and efficiency of chemical purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0048] Figure 1 This is a flow chart of a chemical purification method with inner and outer nested vapor-liquid flash evaporation disclosed in this application;

[0049] Figure 2 This is a specific flow chart of inner and outer nested vapor-liquid flash evaporation disclosed in this application;

[0050] Figure 3 This is a schematic diagram of the structure of a chemical purification device with inner and outer nested vapor-liquid flash evaporation disclosed in this application;

[0051] Figure 4 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] In the chemical and oil refining production processes, it is necessary to purify compounds, such as separating gasoline, diesel and asphalt from petroleum. Different compounds have different volatility, which can be roughly understood as the ease of vaporization of liquid compounds, such as gasoline is more volatile than diesel at the same temperature. A liquid mixture formed by multiple compounds is injected into a tank with a specific pressure and temperature, and part of it will be vaporized into a gas, containing more volatile components; the rest will remain in liquid form, containing more non-volatile components. After multiple stages of operation, the purification operation of the components can be achieved. This process is called flash operation. The existing traditional flash algorithm achieves computational convergence by iterating temperature, vapor phase fraction, etc. Each iteration requires a strict calculation of equilibrium constants and enthalpy, resulting in excessive load on computer memory and processors. At the same time, due to the serious nonlinearity of the strict mechanism model, the calculation process will have serious divergence, resulting in oscillation and collapse of the calculation results. As can be seen from the above, how to realize the nested vapor-liquid flash calculation of the inner and outer layers and improve the quality and efficiency of chemical purification is a problem to be solved in this field.

[0054] See also Figure 1 As shown, the embodiment of the present invention discloses a chemical purification method of inner and outer nested vapor-liquid flash evaporation, which may specifically include:

[0055] Step S11: Calculate the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture, and calculate the equilibrium constants of the components at different temperatures.

[0056] In this embodiment, the mixture components, compound boiling point and operating pressure in the compound parameters are calculated using a preset temperature calculation formula and a vapor phase fraction calculation formula to obtain an initial temperature value and an initial vapor phase fraction value; the temperature calculation formula is:

[0057] ;

[0058] Where P is the current operating pressure, N is the number of mixture components, is the boiling point of the ith component, is the feed composition of the i-th component, T is the initial temperature;

[0059] The vapor phase fraction calculation formula is:

[0060] ;

[0061] in, is the initial value of vapor phase fraction.

[0062] Then, the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to any two temperatures are calculated, and the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to two different temperatures are linearly fitted to construct an equation correlation between enthalpy-equilibrium constant-temperature; the equilibrium constants of each component corresponding to all different temperatures are calculated using the equation correlation.

[0063] For example, taking the calculation of the equilibrium constants of each component at two different temperatures as an example, we calculate the equilibrium constants of the two components at two different temperatures. and The corresponding vapor phase enthalpy and , liquid phase enthalpy and , and the equilibrium constants of each component and , where i represents the component number. The linear relationship between enthalpy and equilibrium constant and temperature can be obtained by the following formula:

[0064] ;

[0065] ;

[0066] ;

[0067] in, and are the vapor phase enthalpy of the mixture and liquid phase enthalpy The partial derivative relationship with temperature is represents the equilibrium constant of component i The partial derivative relationship with temperature. Then, the vapor phase enthalpy of the mixture at any temperature T is , liquid phase enthalpy and component equilibrium constant All can be calculated by the following formula:

[0068] ;

[0069] ;

[0070] .

[0071] Step S12: Calculate the vapor phase component and the liquid phase component based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component.

[0072] In this embodiment, an equilibrium constant and enthalpy model is constructed according to a preset model construction rule; the initial temperature value, the initial vapor phase fraction value, and the equilibrium constant of each component are input into the equilibrium constant and enthalpy model for calculation to obtain vapor phase components and liquid phase components; wherein the calculation formulas for the vapor phase components and the liquid phase components are:

[0073] ;

[0074] ;

[0075] in, and are the vapor phase component and liquid phase component of the i-th component in the vapor phase, is the feed composition of the ith component, is the equilibrium constant of the ith component at the current temperature T, is the initial value of vapor phase fraction.

[0076] Step S13: using the vapor phase component and the liquid phase component to determine whether the vapor-liquid flash inner layer of the chemical mixture converges; if the vapor-liquid flash inner layer of the chemical mixture converges, performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount.

[0077] In this embodiment, if the inner layer of the vapor-liquid flash of the chemical mixture converges, the deviation calculation formula is used to calculate the deviation of the vapor phase component and the liquid phase component; the deviation calculation formula is:

[0078] ;

[0079] in, is the deviation, and N is the number of mixture components.

[0080] Step S14: Determine whether the deviation is less than a preset specific tolerance. If the deviation is less than the preset specific tolerance, end the inner loop, determine the current temperature, current component and current vapor phase fraction, and calculate the enthalpy at the current temperature, current component and current vapor phase fraction.

[0081] In this embodiment, it is determined whether the deviation is less than a preset specific tolerance. If the deviation is not less than the preset specific tolerance, the approximate derivative of the deviation changing with temperature is calculated; the new vapor phase fraction is calculated using the approximate derivative, the deviation, and the initial value of the vapor phase fraction, and the new temperature is calculated based on the new vapor phase fraction; based on the new vapor phase fraction, the new temperature, and the equilibrium constants of each component, the process of calculating the new vapor phase component and the new liquid phase component is repeatedly executed until the deviation is less than the preset specific tolerance.

[0082] Specifically, the formula for calculating the approximate derivative of the deviation with temperature is:

[0083] ;

[0084] The new vapor fraction is estimated :

[0085] ;

[0086] New temperature Predicted by the following formula:

[0087] .

[0088] Step S15: Determine whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, terminate the outer cycle to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

[0089] The specific process of chemical purification of inner and outer nested vapor-liquid flash evaporation proposed in this application is as follows Figure 2 As shown, the steps are as follows: 1. According to the boiling point, composition and known operating pressure of the compounds in the mixture, the initial value of the temperature and the initial value of the vapor phase fraction are weighted and predicted; 2. In the inner nesting, according to the current composition and pressure, the enthalpy and equilibrium constant are calculated at two different temperature points, and then the linear fitting is performed to obtain the linear equation correlation between the enthalpy and equilibrium constant and the temperature; 3. According to the temperature and the vapor phase fraction, combined with the simplified equilibrium constant and enthalpy model, the vapor phase component and the liquid phase component are calculated to determine whether the vapor-liquid flash inner layer of the chemical mixture converges; 4. If the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, execute step 5. If the inner layer of the vapor-liquid flash evaporation of the chemical mixture does not converge, calculate the deviation, predict the new temperature and the new vapor phase fraction based on the deviation, and return to step 3; 5. At this time, the inner nesting converges, return to the outer nesting, determine the current temperature, current components and current vapor phase fraction, calculate the enthalpy at the current temperature, current components and current vapor phase fraction, and determine whether the enthalpy is less than the preset enthalpy value. If it is less than, end the outer cycle to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation, otherwise return to step 2.

[0090] This application simplifies the equilibrium constant and enthalpy model in the inner nested calculation. First, the vapor-liquid composition is calculated with the initial values ​​of temperature and gas fraction, and then the vapor-liquid composition is used as the independent variable to predict the temperature and gas fraction of the next iteration, and this is repeated until the inner layer converges; the outer nesting is based on a strict model for data verification. The existing traditional algorithms and inner and outer layer algorithms are both directly iterative methods of temperature and gas fraction. Through actual code programming, the actual chemical and refining processes were calculated and verified. The results show that the algorithm has extremely fast calculation speed and extremely stable convergence process, and can generally achieve convergence within 100 milliseconds.

[0091] The innovation of this application lies in: simplifying the complex chemical mechanism model into a linear model, greatly improving the calculation speed and convergence stability; directly predicting the new equilibrium temperature and vapor phase fraction through the composition, avoiding the repeated iteration of temperature in the traditional model, and greatly reducing the number of convergence iterations.

[0092] In this embodiment, the initial temperature value and the initial vapor fraction value are calculated according to the compound parameters of the chemical mixture, and the equilibrium constants of the corresponding components at different temperatures are calculated respectively; the vapor phase component and the liquid phase component are calculated based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constants of the components; the vapor phase component and the liquid phase component are used to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, and if the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, the vapor phase component and the liquid phase component are calculated to obtain the deviation amount; it is determined whether the deviation amount is less than a preset specific tolerance, and if the deviation amount is less than the preset specific tolerance, the inner layer cycle is terminated, and the current temperature, current component and current vapor phase fraction are determined, and the enthalpy at the current temperature, the current component and the current vapor phase fraction is calculated; it is determined whether the enthalpy is less than the preset enthalpy value, and if the enthalpy is not less than the preset enthalpy value, the outer layer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation. The present application proposes an algorithm for nested vapor-liquid flash evaporation in inner and outer layers to realize chemical engineering. The initial temperature value and the initial vapor phase fraction value are calculated according to the compound parameters, and the equilibrium constants of the corresponding components at different temperatures are calculated, thereby obtaining the vapor phase components and the liquid phase components to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges. If it converges, return to the outer nesting and calculate the deviation. If the deviation is less than the preset specific tolerance, calculate the enthalpy at the current temperature, current component and current vapor phase fraction. If the enthalpy is not less than the preset enthalpy value, end the outer cycle, realize the calculation of the inner and outer nested vapor-liquid flash evaporation, complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation, improve the calculation speed and the stability of convergence, avoid the repeated iteration of temperature in the traditional model, greatly reduce the number of convergence iterations, and improve the quality and efficiency of chemical purification.

[0093] See also Figure 3As shown, the embodiment of the present invention discloses a chemical purification device with inner and outer nested vapor-liquid flash evaporation, which may specifically include:

[0094] The initial value and equilibrium constant calculation module 11 is used to calculate the initial value of temperature and the initial value of vapor phase fraction according to the compound parameters of the chemical mixture, and respectively calculate the equilibrium constants of each component corresponding to different temperatures;

[0095] A component calculation module 12, for calculating vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component;

[0096] a deviation calculation module 13, for determining whether the vapor-liquid flash inner layer of the chemical mixture converges by using the vapor phase component and the liquid phase component; if the vapor-liquid flash inner layer of the chemical mixture converges, performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount;

[0097] The inner loop ending module 14 is used to determine whether the deviation is less than a preset specific tolerance. If the deviation is less than the preset specific tolerance, the inner loop is ended, and the current temperature, current component and current vapor phase fraction are determined, and the enthalpy under the current temperature, current component and current vapor phase fraction is calculated;

[0098] The outer cycle termination module 14 is used to determine whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, the outer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

[0099] In this embodiment, the initial temperature value and the initial vapor fraction value are calculated according to the compound parameters of the chemical mixture, and the equilibrium constants of the corresponding components at different temperatures are calculated respectively; the vapor phase component and the liquid phase component are calculated based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constants of the components; the vapor phase component and the liquid phase component are used to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, and if the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges, the vapor phase component and the liquid phase component are calculated to obtain the deviation amount; it is determined whether the deviation amount is less than a preset specific tolerance, and if the deviation amount is less than the preset specific tolerance, the inner layer cycle is terminated, and the current temperature, current component and current vapor phase fraction are determined, and the enthalpy at the current temperature, the current component and the current vapor phase fraction is calculated; it is determined whether the enthalpy is less than the preset enthalpy value, and if the enthalpy is not less than the preset enthalpy value, the outer layer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation. The present application proposes an algorithm for nested vapor-liquid flash evaporation in inner and outer layers to realize chemical engineering. The initial temperature value and the initial vapor phase fraction value are calculated according to the compound parameters, and the equilibrium constants of the corresponding components at different temperatures are calculated, thereby obtaining the vapor phase components and the liquid phase components to determine whether the inner layer of the vapor-liquid flash evaporation of the chemical mixture converges. If it converges, return to the outer nesting and calculate the deviation. If the deviation is less than the preset specific tolerance, calculate the enthalpy at the current temperature, current component and current vapor phase fraction. If the enthalpy is not less than the preset enthalpy value, end the outer cycle, realize the calculation of the inner and outer nested vapor-liquid flash evaporation, complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation, improve the calculation speed and the stability of convergence, avoid the repeated iteration of temperature in the traditional model, greatly reduce the number of convergence iterations, and improve the quality and efficiency of chemical purification.

[0100] In some specific embodiments, the initial value and equilibrium constant calculation module 11 may specifically include:

[0101] The calculation module is used to calculate the mixture components, compound boiling point and operating pressure in the compound parameters using a preset temperature calculation formula and a vapor phase fraction calculation formula to obtain an initial temperature value and an initial vapor phase fraction value; the temperature calculation formula is:

[0102] ;

[0103] Where P is the current operating pressure, N is the number of mixture components, is the boiling point of the ith component, is the feed composition of the i-th component, T is the initial temperature;

[0104] The vapor phase fraction calculation formula is:

[0105] ;

[0106] in, is the initial value of vapor phase fraction.

[0107] In some specific embodiments, the initial value and equilibrium constant calculation module 11 may specifically include:

[0108] A correlation building module, used to calculate the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to any two temperatures, and to perform linear fitting on the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to two different temperatures to build an equation correlation between enthalpy-equilibrium constant-temperature;

[0109] The equilibrium constant calculation module is used to calculate the equilibrium constants of each component corresponding to all different temperatures using the equation correlation formula.

[0110] In some specific embodiments, the component calculation module 12 may specifically include:

[0111] A model building module, used to build equilibrium constant and enthalpy models according to preset model building rules;

[0112] The component calculation module is used to input the initial value of temperature, the initial value of vapor phase fraction and the equilibrium constant of each component into the equilibrium constant and enthalpy model for calculation to obtain vapor phase component and liquid phase component.

[0113] In some specific embodiments, the calculation formulas of the vapor phase component and the liquid phase component are:

[0114] ;

[0115] ;

[0116] in, and are the vapor phase component and liquid phase component of the i-th component in the vapor phase, is the feed composition of the ith component, is the equilibrium constant of the ith component at the current temperature T, is the initial value of vapor phase fraction.

[0117] In some specific embodiments, the deviation calculation module 13 may specifically include:

[0118] The deviation calculation module is used to perform deviation calculation on the vapor phase component and the liquid phase component using a deviation calculation formula; the deviation calculation formula is:

[0119] ;

[0120] in, is the deviation, and N is the number of mixture components.

[0121] In some specific embodiments, the inner loop ending module 14 may specifically include:

[0122] An approximate derivative calculation module, used for calculating the approximate derivative of the deviation with temperature if the deviation is not less than a preset specific tolerance;

[0123] A new vapor phase fraction and new temperature calculation module, used to calculate the new vapor phase fraction using the approximate derivative, the deviation and the initial value of the vapor phase fraction, and calculate the new temperature according to the new vapor phase fraction;

[0124] The component calculation module is repeatedly executed to repeatedly execute the process of calculating new vapor phase components and new liquid phase components based on the new vapor phase fraction, the new temperature and the equilibrium constant of each component until the deviation is less than a preset specific tolerance.

[0125] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the chemical purification method of inner and outer nested vapor-liquid flash evaporation performed by the electronic device disclosed in any of the aforementioned embodiments.

[0126] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0127] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon include an operating system 221, a computer program 222 and data 223, etc. The storage method can be temporary storage or permanent storage.

[0128] Among them, the operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20, so as to realize the operation and processing of the data 223 in the memory 22 by the processor 21, which can be Windows, Unix, Linux, etc. In addition to including a computer program that can be used to complete the chemical purification method of inner and outer nested vapor-liquid flash evaporation performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include a computer program that can be used to complete other specific tasks. In addition to including data transmitted from an external device received by the chemical purification device of inner and outer nested vapor-liquid flash evaporation, the data 223 can also include data collected by its own input and output interface 25, etc.

[0129] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0130] Furthermore, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored. When the computer program is loaded and executed by a processor, the steps of the chemical purification method of inner and outer nested vapor-liquid flash evaporation disclosed in any of the aforementioned embodiments are implemented.

[0131] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0132] The above is a detailed introduction to the chemical purification method, device, equipment and storage medium for inner and outer nested vapor-liquid flash evaporation provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A chemical purification method with inner and outer nested vapor-liquid flash evaporation, characterized in that: include: Calculate the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture, and calculate the equilibrium constants of each component at different temperatures; Calculate vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value, and the equilibrium constants of each component; Using the vapor phase component and the liquid phase component to determine whether the vapor-liquid flash inner layer of the chemical mixture converges, if the vapor-liquid flash inner layer of the chemical mixture converges, then performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount; Determine whether the deviation is less than a preset specific tolerance, if the deviation is less than the preset specific tolerance, end the inner loop, determine the current temperature, the current component and the current vapor phase fraction, and calculate the enthalpy at the current temperature, the current component and the current vapor phase fraction; It is determined whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, the outer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

2. The chemical purification method of inner and outer nested vapor-liquid flash evaporation according to claim 1, characterized in that: The step of calculating the initial temperature value and the initial vapor phase fraction value according to the compound parameters of the chemical mixture comprises: The mixture components, compound boiling point and operating pressure in the compound parameters are calculated using the preset temperature calculation formula and vapor phase fraction calculation formula to obtain the initial temperature value and the initial vapor phase fraction value; the temperature calculation formula is: ； Where P is the current operating pressure, N is the number of mixture components, is the boiling point of the ith component, is the feed composition of the i-th component, T is the initial temperature; The vapor phase fraction calculation formula is: ； in, is the initial value of vapor phase fraction.

3. The chemical purification method of inner and outer nested vapor-liquid flash evaporation according to claim 1, characterized in that: The step of calculating the equilibrium constants of the components at different temperatures comprises: Calculate the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to any two temperatures, and perform linear fitting on the vapor phase enthalpy, liquid phase enthalpy and equilibrium constant corresponding to two different temperatures to construct an equation correlation between enthalpy-equilibrium constant-temperature; The equation correlation formula is used to calculate the equilibrium constants of each component at all different temperatures.

4. The chemical purification method of inner-outer nested vapor-liquid flash evaporation according to claim 1, characterized in that: The calculating of the vapor phase component and the liquid phase component based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component comprises: Construct equilibrium constant and enthalpy models according to preset model building rules; The initial value of temperature, the initial value of vapor phase fraction and the equilibrium constant of each component are input into the equilibrium constant and enthalpy model for calculation to obtain vapor phase component and liquid phase component.

5. The chemical purification method of inner-outer nested vapor-liquid flash evaporation according to claim 1, characterized in that: The calculation formulas for the vapor phase component and the liquid phase component are: ； ； in, and are the vapor phase component and liquid phase component of the i-th component in the vapor phase, is the feed composition of the ith component, is the equilibrium constant of the ith component at the current temperature T, is the initial value of vapor phase fraction.

6. The chemical purification method of inner and outer nested vapor-liquid flash evaporation according to claim 5, characterized in that: The performing deviation calculation on the vapor phase component and the liquid phase component comprises: The deviation calculation formula is used to calculate the deviation of the vapor phase component and the liquid phase component; the deviation calculation formula is: ； in, is the deviation, and N is the number of mixture components.

7. The chemical purification method of inner-outer nested vapor-liquid flash evaporation according to any one of claims 1 to 6, characterized in that: After determining whether the deviation is less than a preset specific tolerance, the method further includes: If the deviation is not less than a preset specific tolerance, the approximate derivative of the deviation with temperature is calculated; Calculating a new vapor phase fraction using the approximate derivative, the deviation, and the initial value of the vapor phase fraction, and calculating a new temperature according to the new vapor phase fraction; Based on the new vapor phase fraction, the new temperature and the equilibrium constants of the components, the process of calculating new vapor phase components and new liquid phase components is repeatedly performed until the deviation is smaller than a preset specific tolerance.

8. A chemical purification device with inner and outer nested vapor-liquid flash evaporation, characterized in that: include: The initial value and equilibrium constant calculation module is used to calculate the initial value of temperature and the initial value of vapor phase fraction according to the compound parameters of the chemical mixture, and calculate the equilibrium constants of each component at different temperatures; A component calculation module, used for calculating vapor phase components and liquid phase components based on the initial temperature value, the initial vapor phase fraction value and the equilibrium constant of each component; a deviation calculation module, for determining whether the vapor-liquid flash inner layer of the chemical mixture converges by using the vapor phase component and the liquid phase component; if the vapor-liquid flash inner layer of the chemical mixture converges, performing deviation calculation on the vapor phase component and the liquid phase component to obtain a deviation amount; An inner loop termination module, used for judging whether the deviation is less than a preset specific tolerance, and if the deviation is less than the preset specific tolerance, terminating the inner loop, determining the current temperature, the current component and the current vapor phase fraction, and calculating the enthalpy at the current temperature, the current component and the current vapor phase fraction; The outer cycle termination module is used to determine whether the enthalpy is less than a preset enthalpy value. If the enthalpy is not less than the preset enthalpy value, the outer cycle is terminated to complete the chemical purification of the inner and outer nested vapor-liquid flash evaporation.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the chemical purification method of inner and outer nested vapor-liquid flash evaporation as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein, when the computer program is executed by a processor, the chemical purification method of inner and outer nested vapor-liquid flash evaporation as described in any one of claims 1 to 7 is implemented.

Images