Rectifying tower dynamic simulation method, device, equipment, medium and product

Abstract

The invention discloses a dynamic simulation method, device and equipment for a rectifying tower, a medium and a product, and relates to the field of separation engineering.The method comprises the steps that the fraction of each component in gas-phase discharging and liquid-phase discharging at the current moment and the flow of the gas-phase discharging and the flow of the liquid-phase discharging are input into a differential equation, and the retention volume, retention composition and the total enthalpy value at the next moment are obtained; calculating the fraction of each component in the gas phase discharge at the next moment; obtaining the temperature, the pressure and the gas phase fraction of the next moment and the fraction of each component in the liquid phase discharge according to the temperature, the pressure and the total volume of the current moment and the total enthalpy value, the retention volume and the fraction of each component in the retention liquid of the next moment by adopting a simple UV flash evaporation method; introducing the pressure at the next moment into a tower plate correlation formula to obtain gas and liquid phase discharge flows at the next moment; and if the current moment does not reach the preset moment, entering next moment calculation, so that the accuracy and speed of a solving result can be improved, and the solving difficulty can be reduced.

Description

Technical Field

[0001] The present application relates to the field of separation engineering, and in particular to a distillation tower dynamic simulation method, device, equipment, medium and product. Background Art

[0002] With the advancement of digital twin technology, the use of digital twin models for dynamic simulation in the field of chemical distillation has become one of the key links in optimizing the operation and design of distillation towers. The application of accurate physical dynamic models to dynamic simulation of distillation towers is crucial for developing advanced control strategies and optimizing plant dynamic operation. However, since the first principle model is usually large in scale, highly complex, and time-consuming to calculate, and does not have real-time capabilities, the dynamic Edmister Method (DEM) is used to solve it. However, the results of simulation using DEM are not accurate and difficult to solve. Summary of the invention

[0003] The purpose of this application is to provide a distillation tower dynamic simulation method, device, equipment, medium and product, which can improve the accuracy and speed of solution results and reduce the difficulty of solution.

[0004] To achieve the above objectives, this application provides the following solutions:

[0005] In a first aspect, the present application provides a distillation tower dynamic simulation method, comprising:

[0006] According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, fraction of each component in gas phase feed, fraction of each component in gas phase discharge, fraction of each component in liquid phase feed, fraction of each component in liquid phase discharge, gas phase feed enthalpy value, gas phase discharge enthalpy value, liquid phase feed enthalpy value, liquid phase discharge enthalpy value, material balance differential equation and energy balance differential equation of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment are obtained;

[0007] Calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment;

[0008] A simple UV flash evaporation method is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase output at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment;

[0009] Substitute the pressure at the next moment into the tray correlation equation to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment;

[0010] Determine whether the current moment reaches the preset moment. If so, output the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment;

[0011] If not, update the current moment to enter the next moment, and return to step 1. According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment are obtained;

[0012] The simple UV flash evaporation method is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase discharge at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment, specifically:

[0013] At the current iteration number, the TP flash method is used to process the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retentate at the next moment to obtain the gas phase fraction and the fraction of each component in the liquid phase discharge at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment;

[0014] Calculate the error value according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and determine whether the error value converges;

[0015] If it does not converge, the pressure at the next iteration is obtained based on the pressure at the current iteration and the error value, and then the iteration number is updated to enter the next iteration;

[0016] If converged, the enthalpy of the gas phase and the enthalpy of the liquid phase are calculated, and then the enthalpy of the gas phase, the enthalpy of the liquid phase and the total enthalpy at the next moment are used to determine whether the enthalpy is conserved;

[0017] If conservation is true, the temperature at the next iteration is determined to be the temperature at the next moment, the pressure at the current iteration is determined to be the pressure at the next moment, and the fraction of each component in the liquid phase output at the next iteration is determined to be the fraction of each component in the liquid phase output at the next moment;

[0018] If it is not conserved, the Newton iteration method is used to iteratively update the enthalpy balance equation to obtain the temperature at the next moment, and then the temperature at the current iteration number is determined as the temperature at the next iteration number, and then the iteration number is updated to enter the next iteration.

[0019] In a second aspect, the present application provides a distillation tower dynamic simulation device, comprising:

[0020] A differential algebraic equation module is used to obtain the total enthalpy value at the next moment, the holdup at the next moment, and the fraction of each component in the retentate at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment;

[0021] The fraction update module of each component in the gas phase discharge is used to calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment;

[0022] The simple UV flash evaporation module is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase output at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention volume at the next moment and the fraction of each component in the retention liquid at the next moment by using the simple UV flash evaporation method;

[0023] The discharge flow rate update module is used to bring the pressure at the next moment into the tower plate correlation formula to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment;

[0024] A judgment module is used to judge whether the current moment has reached the preset moment. If so, the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment are output;

[0025] A circulation module, for if no, updating the current moment to enter the next moment, and returning to the step to obtain the total enthalpy value at the next moment, the holdup at the next moment, and the fraction of each component in the holdup liquid at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment;

[0026] The simple UV flash evaporation module specifically comprises:

[0027] The TP flash unit is used to process the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retentate at the next moment by TP flash distillation to obtain the gas phase fraction and the fraction of each component in the liquid phase discharge at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment;

[0028] A convergence judgment unit is used to calculate the error value according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and judge whether the error value converges;

[0029] The iteration unit is used to obtain the pressure at the next iteration number according to the pressure at the current iteration number and the error value if convergence does not occur, and then update the iteration number to enter the next iteration;

[0030] A conservation judgment unit is used to calculate the enthalpy value of the gas phase and the enthalpy value of the liquid phase if convergence occurs, and then judge whether the enthalpy value is conserved according to the enthalpy value of the gas phase, the enthalpy value of the liquid phase and the total enthalpy value at the next moment;

[0031] A determination unit is used to determine, if conservation is maintained, that the temperature at the next iteration number is the temperature at the next moment, the pressure at the current iteration number is the pressure at the next moment, and the fraction of each component in the liquid phase discharge at the next iteration number is the fraction of each component in the liquid phase discharge at the next moment;

[0032] The temperature update unit is used to iteratively update the enthalpy balance equation using the Newton iteration method to obtain the temperature at the next moment if it is not conserved, and then determine the temperature at the current iteration number as the temperature at the next iteration number, and then update the iteration number to enter the next iteration.

[0033] In a third aspect, the present application provides a computer device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement any of the above-described distillation tower dynamic simulation methods.

[0034] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described methods for dynamic simulation of a distillation tower.

[0035] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements any of the above-mentioned distillation tower dynamic simulation methods.

[0036] According to the specific embodiments provided in this application, this application has the following technical effects:

[0037] The present application provides a method, device, equipment, medium and product for dynamic simulation of a distillation tower. The above-mentioned original DEM has the following problems when applied: First, the flash evaporation method (bubble point flash evaporation) adopted therein cannot accurately express the response process of the tower section containing fewer tower plates. When used to calculate the tower section containing fewer tower plates, the calculation result is quite different from the strict UV flash evaporation model. However, the simple UV flash evaporation method provided by the present application fully considers the influence of composition changes on the separation process, gas phase retention, pressure change and energy conservation. Therefore, when the tower section contains fewer tower plates, the calculation result can be close to the strict UV flash evaporation model, thereby improving the accuracy of the solution result; second, the equation system corresponding to the solution of the entire model is a high-exponential differential algebraic equation group, which has a slow solution speed and great difficulty in solving. The present application solves the differential equations of material balance and energy balance respectively, and the model has low difficulty in solving and fast solution speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 A flow chart of a distillation tower dynamic simulation method provided in one embodiment of the present application;

[0040] Figure 2 Flow chart of the simple UV flash evaporation method provided in this application;

[0041] Figure 3 A flowchart of a distillation tower dynamic simulation method provided in one embodiment of the present application;

[0042] Figure 4 This is a specific disturbance diagram of Example 1;

[0043] Figure 5 A comparison chart of pressure results obtained by two calculation updates in Example 1;

[0044] Figure 6 This is a comparison chart of the temperature results updated by the two calculations in Example 1;

[0045] Figure 7 This is a response diagram of the C3 key component in the liquid phase product of the tower section in Example 3;

[0046] Figure 8 The middle part is a response diagram of the C4 key component in the liquid phase product of the tower section in Example 3;

[0047] Fig. 9 A schematic diagram of the structure of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0050] In an exemplary embodiment, Figure 1 and Figure 3 As shown, a distillation tower dynamic simulation method is provided, comprising the following steps, wherein:

[0051] Step 201: According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention amount at the next moment and the fraction of each component in the retention liquid at the next moment are obtained.

[0052] Step 202: Calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment.

[0053] Step 203: Using a simple UV flash evaporation method according to the current temperature, pressure and total volume V of the distillation tower section seg , the total enthalpy value H at the next moment, the retention volume at the next moment, and the fraction of each component in the retained liquid at the next moment to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction, and the fraction of each component in the liquid phase output at the next moment.

[0054] Step 204: Substitute the pressure at the next moment into the tray correlation (known) to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment. Specifically, the pressure is substituted into the tray correlation, and the pressure-flow relationship in the tray correlation is used to update the gas phase discharge flow rate and the liquid phase discharge flow rate at the current moment. The flow rate can be updated by: enthalpy balance algebraic equation, tray correlation with pressure-flow relationship, and the tray correlation is preferably used in this step to accurately express the flow rate change when the pressure changes.

[0055] Step 205: Determine whether the current moment has reached the preset moment. If so, output the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment.

[0056] Step 206: If not, update the current moment to enter the next moment, and return to step 206. According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention amount at the next moment and the fraction of each component in the retention liquid at the next moment are obtained.

[0057] like Figure 2 As shown, step 203 specifically includes:

[0058] Step 2031: At the current iteration number, the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retentate at the next moment are processed by isothermal isobaric flash (TP) to obtain the gas phase fraction and the fraction of each component in the liquid phase output at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment. The purpose of TP flash is to converge the composition and gas phase fraction with the help of TP flash calculation, and simplify the equation group used to judge convergence in UV flash.

[0059] Step 2032: Calculate the error value based on the pressure at the current iteration number, the fraction of each component in the liquid phase output at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and determine whether the error value converges; specifically, determine whether it converges based on the ideal gas state equation.

[0060] Step 2033: If it does not converge, then according to the pressure P and error value P (V seg -V L )-eNRT obtains the pressure P' at the next iteration number, then updates the iteration number and enters the next iteration. Specifically, according to the formula P'=Pa df [P(V seg -V L )-eNRT] calculation, where a df is the adjustment factor, e represents the gas phase fraction, T represents the temperature at the current iteration number, N is the gas phase retention molar mass, and R is the gas constant. df This parameter needs to be manually determined. It determines the pressure range updated by the error. Since the pressure change in the disturbance process is usually small, it is specified that a df A smaller value should be selected. In step 2032 and step 2033, the volume balance of flash evaporation is determined by the ideal gas state equation, and an adjustment factor can be set based on experience, and the pressure is adjusted according to the error to achieve simple iteration of the pressure.

[0061] Step 2034: If converged, the enthalpy of the gas phase and the enthalpy of the liquid phase are calculated, and then whether the enthalpy is conserved is determined based on the enthalpy of the gas phase, the enthalpy of the liquid phase and the total enthalpy at the next moment.

[0062] Step 2035: If conservation is achieved, determine that the temperature at the next iteration number is the temperature at the next moment, the pressure at the current iteration number is the pressure at the next moment, and the fraction of each component in the liquid phase output at the next iteration number is the fraction of each component in the liquid phase output at the next moment.

[0063] Step 2036: If it is not conserved, use Newton's iteration method to balance the enthalpy equation H L +H V -H=0, iterate and update to get the temperature at the next moment, then determine the temperature at the current iteration number as the temperature at the next iteration number, then update the iteration number and enter the next iteration. L Indicates the total enthalpy of the liquid phase in the tower section at the current moment, H V represents the total enthalpy of the gas phase in the tower section at the current moment, and H represents the total enthalpy at the next moment. The process of obtaining the temperature according to the enthalpy balance equation is a well-known process.

[0064] In an exemplary embodiment, according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention amount at the next moment and the fraction of each component in the retention liquid at the next moment are obtained, specifically including:

[0065] The gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed and the fraction of each component in the liquid phase discharge of the distillation tower section at the current moment are input into the differential equation of material balance to obtain the retention amount at the next moment and the fraction of each component in the retention liquid at the next moment.

[0066] The gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, gas phase feed enthalpy value, gas phase discharge enthalpy value, liquid phase feed enthalpy value and liquid phase discharge enthalpy value of the distillation tower section at the current moment are input into the differential equation of energy balance to obtain the total enthalpy value at the next moment. The differential equation of material balance in this process ignores the gas phase retention, only considers the molar retention, and solves the differential equation group of tower section material balance and energy balance on the basis of replacing the derivative of the retention and the molar enthalpy of the retention liquid phase mixture with time in differential form, determines the new molar retention, retention composition and total enthalpy value, reduces the size of the differential equation system, and reduces the difficulty of solving.

[0067] In an exemplary embodiment, the present application regards the tower section as a large tower plate for processing, and before step 201, it also includes: obtaining the retention volume and plate pressure drop Then according to the number of plates in the inner section (n-2) and the formula For retention Scaling to get the scaled retention To maintain the tray characteristics of this section. calculate The specific formula is Pressure drop from plate to plate Pressure drop caused by the clear liquid According to the formula Calculate the total pressure According to the number of plates (n-2) and the formula The total pressure will Scaling is performed to obtain the scaled total pressure drop, and the scaled total pressure drop and pressure are brought into the tower plate correlation formula to update the flow rate.

[0068] In an exemplary embodiment, the fraction of each component in the gas phase discharge at the next moment is calculated based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment, specifically including:

[0069] Calculate the performance absorption coefficient φ based on the plate composition parameters and plate flow parameters of the distillation tower section at the current moment Ai and performance stripping coefficient φ Si ; The plate composition parameters include: top plate gas phase composition, top plate liquid phase composition, bottom plate gas phase composition and bottom plate liquid phase composition; the plate flow parameters include: top plate liquid phase production molar flow, top plate gas phase production molar flow, bottom plate liquid phase production molar flow and bottom plate gas phase production molar flow.

[0070] The fraction of each component in the gas phase discharge at the next moment is calculated based on the performance absorption coefficient, the performance stripping coefficient, the gas phase discharge flow rate of the distillation tower section at the current moment, the fraction of each component in the gas phase feed, the liquid phase feed flow rate, the fraction of each component in the liquid phase feed and the gas phase feed flow rate.

[0071] In an exemplary embodiment, the performance absorption coefficient φ is calculated based on the plate composition parameters and plate flow parameters of the distillation tower section at the current moment. Ai and performance stripping coefficient φ Si (φ Ai and φ Si Its physical meaning is to express the mole fraction of the component in the vapor or liquid flow that is retained in the corresponding flow and still exists when leaving the tower section), specifically:

[0072] According to the formula and formula Calculate, where A eff,i is the effective absorption factor, which represents the calculated value of the average absorption factor along the column section with the trays. eff,iThe expression is: and is the absorption factor of the tower top and bottom plate, and its expression is: and in are the fraction of the i-th component in the top plate gas phase, the fraction of the i-th component in the top plate liquid phase, the fraction of the i-th component in the bottom plate gas phase, and the fraction of the i-th component in the bottom plate liquid phase, respectively. It is the molar flow rate of liquid phase production at the top and bottom of the tower section, the molar flow rate of liquid phase production at the bottom plate, the molar flow rate of gas phase production at the top and bottom, and the molar flow rate of gas phase production at the top and bottom.

[0073] In an exemplary embodiment, the fraction of each component in the gas phase discharge at the next moment is calculated according to the performance absorption coefficient, the performance stripping coefficient, the gas phase discharge flow rate of the distillation tower section at the current moment, the gas phase feed flow rate, the fraction of each component in the gas phase feed, the liquid phase feed flow rate, the fraction of each component in the liquid phase feed and the gas phase feed flow rate. Specifically, according to the formula Calculate the fraction of the i-th component in the gas phase output at the next moment

[0074] In an exemplary embodiment, the error value is calculated according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and whether the error value converges is determined, specifically including:

[0075] According to the fraction x of each component in the liquid phase output at the next iteration number i And the holdup at the next moment calculates the holdup liquid volume of the distillation tower section at the next iteration number; specifically, according to the improved Rackett method (Formula ) Calculate the retained liquid volume V L , where V l is the molar volume, n represents the total number of components in the retained liquid phase, V si is the molar critical volume of the ith component, T c , P c , T r are respectively critical temperature, critical pressure, actual temperature (temperature at the current iteration number), Z RA is the unique constant corresponding to each compound in the equation. The numerical value for sample selection can be obtained from relevant chemical manuals.

[0076] According to the pressure V under the current iteration number seg , the retained liquid volume V at the next iteration number LAnd the total volume calculation error value P(V seg -V L )-eNRT, and judge whether the error value converges, that is, P(V seg -V L )-eNRT is less than le-6.

[0077] In an exemplary embodiment, the differential equation for material balance includes:

[0078] and Among them, M represents the retention amount at the next moment, z i represents the fraction of the i-th component in the retentate at the next moment, t represents the current moment, represents the liquid feed flow rate, Indicates the liquid phase discharge flow rate, represents the gas phase feed flow rate, represents the gas phase discharge flow rate, represents the fraction of the i-th component in the gas phase feed, represents the fraction of the i-th component in the gas phase output, represents the fraction of the i-th component in the liquid feed, represents the fraction of the ith component in the liquid phase. The Gear algorithm is used to solve this equation.

[0079] In an exemplary embodiment, the differential equation for the energy balance is:

[0080] Among them, H represents the total enthalpy value at the next moment, t represents the current moment, represents the liquid feed flow rate, Indicates the liquid phase discharge flow rate, represents the gas phase feed flow rate, represents the gas phase discharge flow rate, represents the gas phase feed enthalpy, represents the gas phase discharge enthalpy, represents the liquid feed enthalpy, represents the liquid phase discharge enthalpy. The Gear algorithm is used to solve this equation.

[0081] This application has the following technical effects:

[0082] 1. This application proposes a simple UV flash evaporation method for the internal segment of DEM, and applies this method to split the DEM equation system, and proposes a new calculation process for the internal segment of DEM. Compared with the existing DEM, the dynamic response process of this application is closer to the strict UV flash evaporation model, and the whole process is simple and easy to operate, overcoming the difficulties in solving differential algebraic systems and the problems of ignoring energy conservation in simple simulations, thereby improving the efficiency of process solutions.

[0083] 2. The differential algebraic equation system solved by the model is decomposed into the differential equation part (differential equations for material balance and differential equations for energy balance) and the algebraic equation part (calculation of gas phase fraction, gas-liquid phase enthalpy, composition calculation, retained liquid phase volume, etc. in simple UV flash evaporation) and solved separately, and the difficulty of solving the model is low.

[0084] 3. The simplified assumption of ignoring gas phase retention is adopted, and the derivatives of the retention volume and the molar enthalpy of the retained liquid phase mixture with respect to time are replaced by differential forms, which reduces the size of the differential equation system, reduces the difficulty of solving, and improves the solution speed.

[0085] 4. On the basis of retaining the original dynamic Edmister method plate correlation formula to calculate the flow rate, the flash evaporation method is replaced with a simple UV flash evaporation. While ignoring the gas phase retention, the enthalpy conservation can still be fully considered.

[0086] 5. Whether in calculating differential equations or in judging convergence based on conservation, enthalpy values ​​are used. Generally, internal energy is used in energy calculations. Here, enthalpy values ​​are used instead of internal energy. The simplified assumption that specific internal energy is equal to specific enthalpy is adopted, and the judgment of internal energy balance is converted to enthalpy balance. The iterative process of temperature, pressure, composition and gas phase fraction is split, which reduces the difficulty of flash evaporation process calculation and improves the speed of flash evaporation solution.

[0087] 6. The present application can be used to accurately and quickly calculate the fraction of each component in the gas phase output of a tower section containing multiple tower plates.

[0088] The present application also provides the following examples to explain the above method in detail:

[0089] Example 1

[0090] In this embodiment, a dfis 0.01, and the Peng-Robinson (PR) method is used to determine whether the enthalpy value is conserved. The disturbance process used is the feed step process of a flash evaporation device. The feed changes from the original quaternary system to a hexahydrocarbon mixture. The tank parameters and the steady-state conditions before the step in the tank are known. In order to improve the stability and speed of the iterative process, the initialization method in the strict UV flash evaporation is used to provide the temperature and pressure at the initial moment. The pressure obtained by the simple UV flash evaporation method in this application is compared with the pressure obtained by the strict UV flash evaporation. Figure 5 The comparison results of the temperature obtained by the simple UV flash evaporation method in this application and the temperature obtained by the strict UV flash evaporation are shown as follows. Figure 6 As shown. Figure 5 and Figure 6 It can be seen that the flash evaporation method used in the present application can achieve similar effects to the strict UV flash evaporation model in terms of dynamic flash evaporation update temperature and pressure, and the final steady-state result calculated is completely consistent with the strict UV flash evaporation model.

[0091] Furthermore, Table 1 and Table 2 respectively list the result comparison and relative error of the time period with larger error in the temperature and pressure update process in Example 1. Figure 4 It can be seen from Table 1 and Table 2 that in the time period with large errors in the response process, the relative error between the pressure calculated at each sampling time and the strict UV flash model does not exceed 5%, and the relative error between the calculated temperature and the strict UV flash model does not exceed 2%. Figure 4 Part (a) shows the feeding condition of the device and the state in the tank (temperature, pressure) before the feeding step in Example 1. Figure 4 Part (b) shows the feeding condition of the device and the state inside the tank after the feeding step in Example 1.

[0092] Table 1 Comparison of pressure results in the time section with large error in Example 1

[0093]

[0094]

[0095] Table 2 Comparison of temperature results in the time period with large errors in Example 1

[0096] Time / s Strict UV flash / ℃ Simple UV flash evaporation / ℃ Relative error % 200.00 112.99 112.26 -0.66 220.00 112.35 111.58 -0.69 240.00 111.73 110.91 -0.74 260.00 111.12 110.27 -0.78 280.00 110.54 109.64 -0.82 300.00 109.98 109.03 -0.87 320.00 109.43 108.44 -0.91 340.00 108.90 107.87 -0.96 360.00 108.39 107.31 -1.00 380.00 107.90 106.78 -1.05 400.00 107.42 106.25 -1.10 420.00 106.95 105.75 -1.14 440.00 106.51 105.26 -1.18 460.00 106.07 104.79 -1.23 480.00 105.66 104.33 -1.27 500.00 105.25 103.89 -1.31 520.00 104.86 103.46 -1.35 540.00 104.48 103.05 -1.39 560.00 104.11 102.65 -1.42 580.00 103.76 102.27 -1.46 600.00 103.42 101.90 -1.49 620.00 103.08 101.54 -1.52 640.00 102.76 101.20 -1.55 660.00 102.45 100.86 -1.58 680.00 102.15 100.54 -1.60 700.00 101.87 100.24 -1.63 720.00 101.58 99.94 -1.65 740.00 101.31 99.65 -1.66 760.00 101.05 99.38 -1.68 780.00 100.80 99.12 -1.70 800.00 100.55 98.86 -1.71

[0097] Example 2

[0098] In order to further emphasize the technical concept of this application, the simple UV flash evaporation method in this application is applied to different separation scenarios. Table 3 shows the starting conditions of three different flash evaporation cases.

[0099] Table 3 Initial conditions for dynamic flash evaporation of the three flash evaporation cases in Example 2

[0100]

[0101] Furthermore, the three cases in Example 2 were calculated using the simple UV flash evaporation method and strict UV flash evaporation of the present application, and Table 4 lists the time consumed by the two flash evaporation methods to calculate the same results for the three scenarios. It can be seen that the simple UV flash evaporation method in the present application can greatly improve the calculation speed of flash evaporation while ensuring the same calculation results.

[0102] Table 4 Comparison of calculation time of two flash evaporation methods

[0103] method Case 1 Case 2 Case 3 Strict UV flash 2.42s 3.83s 4.71s Simple UV flash 1.3s 1.91s 1.96s

[0104] Example 3

[0105] This embodiment uses a C3 and C4 separation tower in a gas separation device of a chemical plant. Before the implementation steps, the initial input conditions of the tower are shown in Table 5;

[0106] Table 5 Initial input conditions for C3 and C4 separation towers used for dynamic simulation

[0107] project Numeric Project (feed) Numeric Feed temperature / K 328.15 <![CDATA[Total flow rate / mol·s -1 > 400 Feed pressure / kPa 2301.32 <![CDATA[Component flow rate / mol·s -1 > Number of plates 56 Propane 36.436 Condenser Full condenser Propylene 111.464 Feeding position 26 Isobutane 89.654 Physical property method PR n-Butane 20.406 <![CDATA[Top product flow rate / mol·s -1 > 147.836 1-Butene 18.659 Reflux ratio 2.73 Isobutylene 18.659 Condenser pressure / kPa 1901.33 trans-2-butene 17.761 Pressure drop in tower / kPa 60 Cis-2-Butene 13.451

[0108] After the distillation tower dynamic simulation method provided by the present application, the dynamic response visualization effect of the key components C3 and C4 in the liquid phase product at the tower outlet is as follows: Figure 7 and Figure 8 As shown, Figure 7 Part (a) shows the dynamic response process of propylene in the liquid phase product at the outlet of the tower section. Figure 7 Part (b) shows the dynamic response process of propane in the liquid phase product at the outlet of the tower section. Figure 8 Part (a) shows the dynamic response process of the components in the liquid product at the outlet of the tower section. Figure 8 Part (b) shows the dynamic response process of the component 1-butene in the liquid phase product at the outlet of the tower section.

[0109] from Figure 5 and Figure 6 The comparison of the results shows that the flash evaporation method used in this application can achieve a similar effect as the strict UV flash evaporation model in dynamic flash evaporation calculation, and reduces the calculation time. On the basis of simplifying the iterative process, the dynamic solution results still maintain stable calculation accuracy, which helps to improve the efficiency of dynamic simulation. Figure 7 and Figure 8It can be concluded that the dynamic response process of the simplified distillation tower dynamic simulation method used in this application is closer to the strict UV flash evaporation model than DEM, and the whole process is simple and easy to operate, overcoming the problems of difficulty in solving differential algebraic systems and ignoring energy conservation in simplified simulations. Compared with DEM, better dynamic response results can be obtained.

[0110] Based on the same inventive concept, the embodiment of the present application also provides a distillation tower dynamic simulation device for implementing the distillation tower dynamic simulation method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more distillation tower dynamic simulation device embodiments provided below can refer to the limitations of the distillation tower dynamic simulation method above, and will not be repeated here.

[0111] In an exemplary embodiment, a distillation tower dynamic simulation device is provided, comprising:

[0112] The differential algebraic equation module is used to obtain the total enthalpy value at the next moment, the retention volume at the next moment, and the fraction of each component in the retentate at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment.

[0113] The module for updating the fraction of each component in the gas phase discharge is used to calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate of the distillation tower section at the current moment, the fraction of each component in the gas phase feed, the liquid phase feed flow rate, the fraction of each component in the liquid phase feed and the gas phase feed flow rate.

[0114] The simple UV flash evaporation module is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase output at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention volume at the next moment and the fraction of each component in the retention liquid at the next moment by using the simple UV flash evaporation method.

[0115] The discharge flow rate update module is used to bring the pressure at the next moment into the tower plate correlation formula to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment.

[0116] The judgment module is used to judge whether the current moment has reached the preset moment. If so, it outputs the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment.

[0117] A circulation module is used for updating the current moment and entering the next moment if no, and returning to the step to obtain the total enthalpy value at the next moment, the retention amount at the next moment and the fraction of each component in the retained liquid at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance of the distillation tower section at the current moment.

[0118] The simple UV flash evaporation module specifically comprises:

[0119] The TP flash unit is used to process the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retained liquid at the next moment by TP flash distillation to obtain the gas phase fraction and the fraction of each component in the liquid phase discharge at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment.

[0120] The convergence judgment unit is used to calculate the error value according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the retention volume at the next moment and the total volume of the distillation tower section at the current moment, and judge whether the error value converges.

[0121] The iteration unit is used to obtain the pressure at the next iteration number based on the pressure at the current iteration number and the error value if convergence does not occur, and then update the iteration number to enter the next iteration.

[0122] The conservation judgment unit is used to calculate the enthalpy value of the gas phase and the enthalpy value of the liquid phase if convergence occurs, and then judge whether the enthalpy value is conserved according to the enthalpy value of the gas phase, the enthalpy value of the liquid phase and the total enthalpy value at the next moment.

[0123] The determination unit is used to determine, if conservation is maintained, that the temperature at the next iteration number is the temperature at the next moment, the pressure at the current iteration number is the pressure at the next moment, and the fraction of each component in the liquid phase output at the next iteration number is the fraction of each component in the liquid phase output at the next moment.

[0124] The temperature update unit is used to iteratively update the enthalpy balance equation using the Newton iteration method to obtain the temperature at the next moment if it is not conserved, and then determine the temperature at the current iteration number as the temperature at the next iteration number, and then update the iteration number to enter the next iteration.

[0125] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig. 9 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store distillation tower dynamic simulation data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a distillation tower dynamic simulation method is implemented.

[0126] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the above-mentioned method embodiments when executing the computer program.

[0127] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0128] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the above-mentioned method embodiments are implemented.

[0129] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0130] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0131] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0132] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A distillation tower dynamic simulation method, characterized in that: The distillation tower dynamic simulation method comprises: According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, fraction of each component in gas phase feed, fraction of each component in gas phase discharge, fraction of each component in liquid phase feed, fraction of each component in liquid phase discharge, gas phase feed enthalpy value, gas phase discharge enthalpy value, liquid phase feed enthalpy value, liquid phase discharge enthalpy value, material balance differential equation and energy balance differential equation of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment are obtained; Calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment; A simple UV flash evaporation method is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase output at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment; Substitute the pressure at the next moment into the tray correlation equation to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment; Determine whether the current moment reaches the preset moment. If so, output the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment; If not, update the current moment to enter the next moment, and return to step 1. According to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance and the differential equation of energy balance, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment are obtained; The simple UV flash evaporation method is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase discharge at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment, specifically: At the current iteration number, the TP flash method is used to process the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retentate at the next moment to obtain the gas phase fraction and the fraction of each component in the liquid phase discharge at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment; Calculate the error value according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and determine whether the error value converges; If it does not converge, the pressure at the next iteration is obtained based on the pressure at the current iteration and the error value, and then the iteration number is updated to enter the next iteration; If converged, the enthalpy of the gas phase and the enthalpy of the liquid phase are calculated, and then the enthalpy of the gas phase, the enthalpy of the liquid phase and the total enthalpy at the next moment are used to determine whether the enthalpy is conserved; If conservation is true, the temperature at the next iteration is determined to be the temperature at the next moment, the pressure at the current iteration is determined to be the pressure at the next moment, and the fraction of each component in the liquid phase output at the next iteration is determined to be the fraction of each component in the liquid phase output at the next moment; If it is not conserved, the Newton iteration method is used to iteratively update the enthalpy balance equation to obtain the temperature at the next moment, and then the temperature at the current iteration number is determined as the temperature at the next iteration number, and then the iteration number is updated to enter the next iteration.

2. The distillation tower dynamic simulation method according to claim 1, characterized in that: The total enthalpy value at the next moment, the holdup at the next moment, and the fraction of each component in the retentate at the next moment are obtained according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment, specifically including: Input the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, fraction of each component in gas phase feed, fraction of each component in gas phase discharge, fraction of each component in liquid phase feed and fraction of each component in liquid phase discharge of the distillation tower section at the current moment into the differential equation of material balance to obtain the holdup at the next moment and the fraction of each component in the holdup liquid at the next moment; The gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, gas phase feed enthalpy value, gas phase discharge enthalpy value, liquid phase feed enthalpy value and liquid phase discharge enthalpy value of the distillation tower section at the current moment are input into the differential equation of energy balance to obtain the total enthalpy value at the next moment.

3. The distillation tower dynamic simulation method according to claim 1, characterized in that: Based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, fraction of each component in the liquid phase feed of the distillation tower section at the current moment, the fraction of each component in the gas phase discharge at the next moment is calculated, specifically including: The performance absorption coefficient and the performance stripping coefficient are calculated according to the plate composition parameters and plate flow parameters of the distillation tower section at the current moment; the plate composition parameters include: top plate gas phase composition, top plate liquid phase composition, bottom plate gas phase composition and bottom plate liquid phase composition; the plate flow parameters include: top plate liquid phase production molar flow, top plate gas phase production molar flow, bottom plate liquid phase production molar flow and bottom plate gas phase production molar flow; The fraction of each component in the gas phase discharge at the next moment is calculated based on the performance absorption coefficient, the performance stripping coefficient, the gas phase discharge flow rate of the distillation tower section at the current moment, the fraction of each component in the gas phase feed, the liquid phase feed flow rate, the fraction of each component in the liquid phase feed and the gas phase feed flow rate.

4. The distillation tower dynamic simulation method according to claim 1, characterized in that: The error value is calculated based on the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and whether the error value converges is determined, including: Calculate the retained liquid volume of the distillation tower section at the next iteration number according to the fraction of each component in the liquid phase output at the next iteration number and the retention volume at the next moment; The error value is calculated according to the pressure at the current iteration number, the retained liquid volume at the next iteration number, and the total volume of the distillation tower section at the current moment, and it is determined whether the error value converges.

5. The distillation tower dynamic simulation method according to claim 2, characterized in that: The differential equations for material balance include: and Among them, M represents the retention amount at the next moment, Z i represents the fraction of the i-th component in the retentate at the next moment, t represents the current moment, represents the liquid feed flow rate, Indicates the liquid phase discharge flow rate, represents the gas phase feed flow rate, represents the gas phase discharge flow rate, represents the fraction of the i-th component in the gas phase feed, represents the fraction of the i-th component in the gas phase output, represents the fraction of the i-th component in the liquid feed, It represents the fraction of the i-th component in the liquid phase output.

6. The distillation tower dynamic simulation method according to claim 2, characterized in that: The differential equation for energy balance is: Among them, H represents the total enthalpy value at the next moment, t represents the current moment, represents the liquid feed flow rate, Indicates the liquid phase discharge flow rate, represents the gas phase feed flow rate, represents the gas phase discharge flow rate, represents the gas phase feed enthalpy, represents the gas phase discharge enthalpy, represents the liquid feed enthalpy, It represents the liquid phase discharge enthalpy.

7. A distillation tower dynamic simulation device, characterized in that: The distillation tower dynamic simulation device comprises: A differential algebraic equation module is used to obtain the total enthalpy value at the next moment, the holdup at the next moment, and the fraction of each component in the retentate at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment; The fraction update module of each component in the gas phase discharge is used to calculate the fraction of each component in the gas phase discharge at the next moment based on the gas phase discharge flow rate, gas phase feed flow rate, fraction of each component in the gas phase feed, liquid phase feed flow rate, and fraction of each component in the liquid phase feed of the distillation tower section at the current moment; The simple UV flash evaporation module is used to obtain the temperature at the next moment, the pressure at the next moment, the gas phase fraction and the fraction of each component in the liquid phase output at the next moment according to the temperature, pressure and total volume of the distillation tower section at the current moment, the total enthalpy value at the next moment, the retention volume at the next moment and the fraction of each component in the retention liquid at the next moment by using the simple UV flash evaporation method; The discharge flow rate update module is used to bring the pressure at the next moment into the tower plate correlation formula to obtain the gas phase discharge flow rate at the next moment and the liquid phase discharge flow rate at the next moment; A judgment module is used to judge whether the current moment has reached the preset moment. If so, the temperature at the next moment, the pressure at the next moment, the gas phase fraction, the fraction of each component in the gas phase discharge at the next moment, the fraction of each component in the liquid phase discharge at the next moment, the gas phase discharge flow rate at the next moment, and the liquid phase discharge flow rate at the next moment are output; A circulation module, for if no, updating the current moment to enter the next moment, and returning to the step to obtain the total enthalpy value at the next moment, the holdup at the next moment, and the fraction of each component in the holdup liquid at the next moment according to the gas phase feed flow rate, gas phase discharge flow rate, liquid phase discharge flow rate, liquid phase feed flow rate, the fraction of each component in the gas phase feed, the fraction of each component in the gas phase discharge, the fraction of each component in the liquid phase feed, the fraction of each component in the liquid phase discharge, the gas phase feed enthalpy value, the gas phase discharge enthalpy value, the liquid phase feed enthalpy value, the liquid phase discharge enthalpy value, the differential equation of material balance, and the differential equation of energy balance of the distillation tower section at the current moment; The simple UV flash evaporation module specifically comprises: The TP flash unit is used to process the temperature and pressure of the distillation tower section at the current iteration number, the total volume at the current moment, the total enthalpy value at the next moment, and the fraction of each component in the retentate at the next moment by TP flash distillation to obtain the gas phase fraction and the fraction of each component in the liquid phase discharge at the next iteration number; the temperature at the initial iteration number is the temperature at the current moment, and the pressure at the initial iteration number is the pressure at the current moment; A convergence judgment unit is used to calculate the error value according to the pressure at the current iteration number, the fraction of each component in the liquid phase discharge at the next iteration number, the holdup at the next moment, and the total volume of the distillation tower section at the current moment, and judge whether the error value converges; The iteration unit is used to obtain the pressure at the next iteration number according to the pressure at the current iteration number and the error value if convergence does not occur, and then update the iteration number to enter the next iteration; A conservation judgment unit is used to calculate the enthalpy value of the gas phase and the enthalpy value of the liquid phase if convergence occurs, and then judge whether the enthalpy value is conserved according to the enthalpy value of the gas phase, the enthalpy value of the liquid phase and the total enthalpy value at the next moment; A determination unit is used to determine, if conservation is maintained, that the temperature at the next iteration number is the temperature at the next moment, the pressure at the current iteration number is the pressure at the next moment, and the fraction of each component in the liquid phase discharge at the next iteration number is the fraction of each component in the liquid phase discharge at the next moment; The temperature update unit is used to iteratively update the enthalpy balance equation using the Newton iteration method to obtain the temperature at the next moment if it is not conserved, and then determine the temperature at the current iteration number as the temperature at the next iteration number, and then update the iteration number to enter the next iteration.

8. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the distillation tower dynamic simulation method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the distillation tower dynamic simulation method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the distillation tower dynamic simulation method according to any one of claims 1 to 6 is implemented.

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