An isothermal isobaric flash calculation method and device, electronic equipment and storage medium

Abstract

This application discloses an isothermal and isobaric flash evaporation calculation method, apparatus, electronic device, and storage medium. Specifically, it involves acquiring multiple system parameters of a non-ideal system, estimating the phase equilibrium constant of the non-ideal system to obtain an initial value for the phase equilibrium constant; based on a gas-liquid two-phase flash evaporation model, the initial value, and multiple system parameters, analyzing whether the feed exhibits liquid-phase stability; if the feed does not exhibit liquid-phase stability, analyzing whether the feed exhibits gas-phase stability; if the feed does not exhibit gas-phase stability, performing gas-liquid two-phase flash evaporation calculations on the feed, obtaining and outputting the calculation results. Compared to existing technologies, this application enables the calculation results to more closely approximate actual conditions.

Description

Technical Field

[0001] This application relates to the field of chemical production technology, and more specifically, to an isothermal and isobaric flash evaporation calculation method, apparatus, electronic equipment, and storage medium. Background Technology

[0002] Flash evaporation utilizes the principle of boiling point. At higher pressures, liquids have higher boiling points, requiring more heat to reach that point. When the pressure decreases, some sensible heat is released, and this energy is absorbed as latent heat, causing a portion of the liquid to rapidly convert into vapor. Isothermal flash evaporation refers to the phenomenon where, at a given temperature, a saturated liquid partially converts into vapor when the pressure decreases. Specifically, when a high-pressure saturated liquid enters a lower-pressure container, the sudden pressure drop causes a portion of the liquid to convert into vapor; this process is called flash evaporation.

[0003] In chemical production systems, isothermal and isobaric flash evaporation calculations are needed to determine the composition and quantity of the gas and liquid phases after phase separation of the mixture at a certain temperature and pressure. However, in non-ideal systems where the actual solution deviates significantly from the ideal solution model, the extremely large or small activity coefficients of infinite dilution components cause large variations in the liquid phase fugacity coefficient during the calculation process, making it difficult to converge the calculation results. Consequently, accurate calculation results are hard to obtain, and the production control system cannot implement stable control of the chemical production system. Summary of the Invention

[0004] In view of this, this application provides an isothermal and isobaric flash evaporation calculation method, apparatus, electronic device, and storage medium for performing isothermal and isobaric flash evaporation calculations on non-ideal conditions to obtain accurate calculation results, so that the production control system can implement stable control of the chemical production process based on the calculation results.

[0005] To achieve the above objectives, the following solution is proposed:

[0006] An isothermal and isobaric flash evaporation calculation method, applied to electronic equipment, is used to calculate the composition and quantity of gas and liquid phases after phase separation in a non-ideal system. The isothermal and isobaric flash evaporation calculation method includes the following steps:

[0007] Obtain multiple system parameters of the non-ideal system, including the composition of the feed, as well as the system temperature and system pressure of the non-ideal system;

[0008] The phase equilibrium constant of the non-ideal system is estimated to obtain an initial value for the phase equilibrium constant;

[0009] Based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters, the analysis is performed to determine whether the feed of the non-ideal system has liquid phase stability. If it has liquid phase stability, the analysis results are output, and the initial value is corrected to obtain the first corrected value of the phase equilibrium parameter.

[0010] If the feed does not have liquid phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value and the multiple system parameters, the analysis is performed to determine whether the feed has gas phase stability. If it has gas phase stability, the analysis result is output, and the first correction value is corrected to obtain the second correction value of the phase equilibrium parameter.

[0011] If the feed does not have gas-phase stability, gas-liquid two-phase flash evaporation calculations are performed on the feed based on the gas-liquid two-phase flash evaporation model, the second correction value, and the multiple system parameters, and the calculation results are obtained and output.

[0012] Optionally, the gas-liquid two-phase flash evaporation model includes a mass conservation equation, a phase equilibrium equation, a composition normalization equation, and a heat conservation equation.

[0013] Optionally, the heat conservation equation is the Rachford-Rice equation.

[0014] Optionally, the step of analyzing whether the feed of the non-ideal system has liquid-phase stability based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters, and outputting the analysis results if liquid-phase stability is found, and correcting the initial value to obtain the first corrected value of the phase equilibrium parameter, includes the following steps:

[0015] Calculate the first liquid phase fugacity coefficient based on the composition, the system temperature, and the system pressure;

[0016] The virtual gas phase composition is calculated based on the initial value of the phase equilibrium constant;

[0017] The sum of the virtual gas phase compositions is calculated based on the aforementioned virtual gas phase compositions;

[0018] The normalized gas phase composition is calculated based on the virtual gas phase composition and the sum of the virtual gas phase compositions;

[0019] The first gas phase fugacity coefficient is calculated based on the normalized gas phase composition, the system temperature, and the system pressure.

[0020] The initial value of the phase equilibrium constant is updated based on the first liquid phase fugacity coefficient and the first gas phase fugacity coefficient;

[0021] The initial value is judged to determine whether it converges. If it does not converge, the process returns to the step of calculating the virtual gas phase composition based on the initial value of the phase equilibrium constant. If it converges, the subsequent operation is performed, and the final initial value is used as the first correction value.

[0022] The feed is judged based on the sum of the virtual gas phase composition. If the sum of the virtual gas phase composition is less than or equal to zero, the feed has liquid phase stability; otherwise, it does not have liquid phase stability.

[0023] Optionally, if the feed does not have liquid-phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value, and the multiple system parameters, an analysis is performed to determine whether the feed has gas-phase stability. If it has gas-phase stability, the analysis result is output, and the first correction value is corrected to obtain a second correction value for the phase equilibrium parameter. This includes the following steps:

[0024] Calculate the second gas phase fugacity coefficient based on the composition, the system temperature, and the system pressure;

[0025] The virtual liquid phase composition is calculated based on the first correction value of the phase equilibrium constant;

[0026] The sum of the virtual liquid phase compositions is calculated based on the aforementioned virtual liquid phase composition;

[0027] The normalized liquid phase composition is calculated based on the virtual liquid phase composition and the sum of the virtual liquid phase compositions;

[0028] The second liquid phase fugacity coefficient is calculated based on the normalized liquid phase composition, the system temperature, and the system pressure.

[0029] The first correction value of the phase equilibrium constant is updated based on the second liquid phase fugacity coefficient and the second gas phase fugacity coefficient;

[0030] If the first correction value does not converge, the process returns to the step of calculating the virtual liquid phase composition based on the first correction value of the phase equilibrium constant. If the process converges, the subsequent operation is performed, and the final first correction value is used as the second correction value.

[0031] The feed is judged based on the sum of the virtual liquid phase composition. If the sum of the virtual liquid phase composition is less than or equal to zero, the feed has gas phase stability; otherwise, it does not have gas phase stability.

[0032] Optionally, if the feed does not have gas-phase stability, then based on the second correction value of the gas-liquid two-phase flash evaporation model and the multiple system parameters, a gas-liquid two-phase flash evaporation calculation is performed on the feed to obtain and output the calculation results, including the following steps:

[0033] Determine whether the second correction value makes the flash evaporation problem valid;

[0034] If the aforementioned flash evaporation problem does not apply, then the second correction value is adjusted;

[0035] If the flash evaporation problem holds true, then the second correction value is iteratively processed based on the heat conservation equation to obtain an iterative reference value;

[0036] The range between the second correction value and the iterative reference value is divided into multiple numerical segments, and then based on the constraint value corresponding to each numerical segment, the process continues until the constraint value converges.

[0037] When the constraint value converges, the calculation result is output.

[0038] Optionally, if the flash evaporation problem does not exist, the second correction value is adjusted, including the following steps:

[0039] The sum of the virtual gas phase composition and the sum of the virtual liquid phase composition of the feed are calculated based on the second correction value;

[0040] The second correction value is adjusted based on the sum of the virtual gas phase composition and the sum of the virtual liquid phase composition.

[0041] An isothermal and isobaric flash evaporation calculation device, applied in electronic equipment, is used to calculate the composition and quantity of gas and liquid phases after phase separation in a non-ideal system. The isothermal and isobaric flash evaporation calculation device includes:

[0042] The parameter acquisition module is configured to acquire multiple system parameters of the non-ideal system, including the composition of the feed, as well as the system temperature and system pressure of the non-ideal system;

[0043] The constant estimation module is configured to estimate the phase equilibrium constant of the non-ideal system to obtain an initial value of the phase equilibrium constant;

[0044] The liquid phase stability test module is configured to analyze whether the feed of the non-ideal system has liquid phase stability based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters. If it has liquid phase stability, the analysis result is output, and the initial value is corrected to obtain the first corrected value of the phase equilibrium parameter.

[0045] The gas phase stability testing module is configured to analyze whether the feed has gas phase stability based on the gas-liquid two-phase flash evaporation model, the first correction value, and the multiple system parameters if the feed does not have liquid phase stability. If the feed has gas phase stability, the analysis result is output, and the first correction value is corrected to obtain the second correction value of the phase equilibrium parameter.

[0046] The flash calculation execution module is configured to perform gas-liquid two-phase flash calculations on the feed based on the gas-liquid two-phase flash model, the second correction value, and the plurality of system parameters if the feed does not have gas-phase stability, and to obtain and output the calculation results.

[0047] An electronic device includes at least one processor and a memory connected to the processor, wherein:

[0048] The memory is used to store computer programs or instructions;

[0049] The processor is used to execute the computer program or instructions to enable the electronic device to implement the isothermal and isobaric flash evaporation calculation method as described above.

[0050] A computer-readable storage medium is applied to an electronic device, the storage medium carrying one or more computer programs that can be executed by the electronic device to enable the electronic device to perform the isothermal and isobaric flash evaporation calculation method as described above.

[0051] As can be seen from the above technical solution, this application discloses an isothermal and isobaric flash evaporation calculation method, apparatus, electronic device, and storage medium. This method and apparatus are applied to electronic devices, specifically involving: acquiring multiple system parameters of a non-ideal system; estimating the phase equilibrium constant of the non-ideal system to obtain an initial value of the phase equilibrium constant; analyzing whether the feed of the non-ideal system has liquid-phase stability based on a gas-liquid two-phase flash evaporation model, the initial value, and multiple system parameters, and correcting the initial value to obtain a first corrected value for the phase equilibrium parameter; if the feed does not have liquid-phase stability, analyzing whether the feed has gas-phase stability based on the gas-liquid two-phase flash evaporation model, the first corrected value, and multiple system parameters, and correcting the first corrected value to obtain a second corrected value for the phase equilibrium parameter; if the feed does not have gas-phase stability, performing a gas-liquid two-phase flash evaporation calculation on the feed based on the gas-liquid two-phase flash evaporation model, the second corrected value, and multiple system parameters, and obtaining and outputting the calculation results. Compared with existing technologies, this application uses a rigorous thermodynamic model to determine the phase state, which makes the calculation results closer to the actual situation, and enables the production control system to implement stable control of the chemical production process based on the calculation results.

[0052] Furthermore, compared to existing technologies, this application utilizes a batch trial method and a selection criterion in gas-phase stability testing and gas-liquid two-phase flash evaporation calculations, which effectively avoids fluctuations in the iterative process and improves the robustness of the algorithm. Moreover, the method of adjusting the K value ensures that the Rachford-Rice equation has a solution when the system is confirmed to be a gas-liquid two-phase system, guaranteeing that the iteration can continue. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating an isothermal and isobaric flash evaporation calculation method according to an embodiment of this application;

[0055] Figure 2 This is a flowchart of the liquid phase testing process according to an embodiment of this application;

[0056] Figure 3 This is a flowchart of the gas phase testing process according to an embodiment of this application;

[0057] Figure 4 This is a flowchart illustrating the gas-liquid two-phase flash evaporation calculation process in an embodiment of this application.

[0058] Figure 5 This is a block diagram of an isothermal and isobaric flash evaporation calculation device according to an embodiment of this application;

[0059] Figure 6 This is a block diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0061] This application performs flash evaporation calculations based on the following gas-liquid two-phase flash evaporation model, which controls the mass conservation equation, phase equilibrium equation, composition normalization equation, and heat conservation equation. These are detailed below:

[0062] The mass conservation equation is:

[0063] Fz i=Vy i +Lx i

[0064] In the formula, F is the molar flow rate of the feed; z i y represents the molar composition of feed composition i; V represents the molar flow rate of the gas phase; i Let be the molar composition of the gas phase i; L be the molar flow rate of the liquid phase; x i Let i be the molar composition of the liquid phase.

[0065] The phase equilibrium equation is:

[0066] y i =K i x i

[0067] In the formula, K i Let be the phase equilibrium constant of component i.

[0068] The normalized equation is as follows:

[0069] ∑y i =1

[0070] ∑x i =1

[0071] The heat conservation equation is:

[0072] FH F +Q=VH V +LH L

[0073] In the formula, H F Q is the molar enthalpy of the feed; Q is the additional heat flow provided; H is the molar enthalpy of the feed. V The molar enthalpy of the gas phase; H L The molar enthalpy is the value of the liquid phase.

[0074] From the mass conservation equation, phase equilibrium equation, and composition normalization equation, we can obtain...

[0075]

[0076] In the formula, ψ is the gas phase fraction ψ=V / F.

[0077] Subtracting the two equations above, we obtain the Rachford-Rice equation:

[0078]

[0079] Because the Rachford-Rice equation has good convergence, iterative solutions to the equation are chosen to solve the flash evaporation model. Based on the above model, the following specific implementation method is proposed.

[0080] Figure 1 This is a flowchart illustrating an isothermal and isobaric flash evaporation calculation method according to an embodiment of this application.

[0081] like Figure 1 As shown, the isothermal and isobaric flash evaporation calculation method provided in this embodiment is applied to an electronic device for flash evaporation calculations on non-ideal systems. This electronic device can be understood as a computer, server, cloud platform, or controller or embedded device of a chemical production system with data computing and information processing capabilities. The calculation method includes the following specific steps:

[0082] S1. Obtain multiple system parameters for a non-ideal system.

[0083] The system parameters include, but are not limited to, the composition of the system feed, as well as the system temperature and system pressure.

[0084] S2. Estimate the phase equilibrium parameter K for the non-ideal system.

[0085] The phase equilibrium parameter K of the non-ideal system is obtained through calculations performed according to preset steps. There are two methods for estimating the initial value of the phase equilibrium constant K:

[0086] ①Wilson correlation;

[0087] K i =exp(5.373*(1+ω) i )*(1-1 / Tr i ) / Pr i

[0088] In the formula, ω i Tr is the eccentricity factor that makes up i; i The comparison temperature of component i; Pr i The comparative pressure that makes up i.

[0089] ② Assuming an ideal gas and ideal solution model, calculate the K value using the saturated vapor pressure method provided by the process simulation software.

[0090] K i =P i s / P

[0091] In the formula, P i s Let be the saturated vapor pressure of component i; P is the system pressure.

[0092] The approach adopted in this invention is to prioritize method ①, and to use method ② if method ① cannot be used due to missing parameters.

[0093] S3. Determine whether the feed to the non-ideal system has liquid-phase stability.

[0094] Based on a gas-liquid two-phase flash evaporation model, the initial value of the phase equilibrium constant, and the aforementioned system parameters, the analysis examines whether the feed to a non-ideal system exhibits liquid-phase stability. If liquid-phase stability is found, the analysis results are output, and the initial value of the phase equilibrium constant is corrected to obtain the first corrected value of the phase equilibrium parameters. The specific process is as follows: Figure 2 As shown:

[0095] 1. Composition of the feed z i The first liquid phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0096] 2. Calculate the virtual gas phase composition Y i =z i K i ;

[0097] 3. Calculate the sum of the virtual gas phase compositions: SumY = ∑Y i ;

[0098] 4. Calculate the normalized gas phase composition y i =Y i / SumY;

[0099] 5. Composed of normalized gas phase y i The first gas phase fugacity coefficient was obtained by calculating the system temperature T and system pressure.

[0100] 6. Update phase equilibrium constants

[0101] 7. Repeat steps 2 to 6 until the initial values ​​of the phase equilibrium parameters mentioned above converge.

[0102] During the liquid phase stability test, when the above phase equilibrium parameters converge, if SumY<=0, the feed is liquid phase and the virtual gas phase composition is output; if SumY>0, it indicates that there is no liquid phase stability, and the next step of gas phase stability test is performed.

[0103] S4. Determine whether the feed to the non-ideal system has gas-phase stability.

[0104] If the feed does not have liquid-phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value, and multiple system parameters, the gas-phase stability of the feed is analyzed. If gas-phase stability is achieved, the analysis results are output, and the first correction value is corrected to obtain the second correction value for the phase equilibrium parameters. Figure 3 As shown.

[0105] 1. Composed of feed components z i The second gas phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0106] 2. Calculate the virtual liquid phase composition X i =z i / K i ;

[0107] 3. Calculate the sum of the virtual liquid phase compositions: SumX = ∑X i ;

[0108] 4. Calculate the normalized liquid phase composition x i =X i / SumX;

[0109] 5. Composed of normalized liquid phase x i The second liquid phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0110] 6. Calculate the reference value of the phase equilibrium constant for the next round.

[0111] 7. Use the batch trial method to test K in this round. i to The average is divided into N test Segments (2-20 optional) are obtained

[0112] 8. By Perform steps 2-6 to obtain the K value for the next round.

[0113] 9. Calculate and compare Find one of them The smallest set of K values ​​K i min As the K value for the next round, As the next round

[0114] 10. Repeat steps 7 to 9 until the first correction value of the phase equilibrium parameters mentioned above converges.

[0115] During the gas phase stability test, when the first correction value converges, if SumX <= 0, the feed is in the gas phase and the virtual liquid phase composition is output; if SumX > 0, it indicates that the feed is not a pure gas phase, and the next step of gas-liquid two-phase flash evaporation calculation is performed.

[0116] S5. Perform gas-liquid two-phase flash evaporation calculations on the feed.

[0117] If the feed lacks gas-phase stability, gas-liquid two-phase flash evaporation calculations are performed on the feed based on the second correction value of the gas-liquid two-phase flash evaporation model and multiple system parameters. The calculation results are then obtained and output, such as... Figure 4 As shown.

[0118] 1. The K value output by the gas phase stability test module is input into the gas-liquid two-phase flash evaporation module as the initial value;

[0119] 2. Determine if the K value satisfies the flash evaporation problem. If not, adjust the K value as follows:

[0120] 2-1. Calculate SumX = ∑z from the value of K. i / K i And SumY=∑z i *K i If both SumX and SumY are greater than 1, no adjustment is needed, and proceed directly to step (3); otherwise, skip to step (2.2).

[0121] 2-2. If SumX < 1, then the coefficient C = SumX 0.9 *SumY -0.1 If SumY < 1, then the coefficient C = SumX 0.1 *SumY -0.9 ;

[0122] 2-3. Adjust the K value, K i =K i *C;

[0123] 3. Solve the Rachford-Rice equation using the trial-and-error method to obtain the reference values ​​for the next iteration.

[0124] 4. Use the batch testing method to test K in this round. i to Divide the average into Ntest ​​segments (2 to 20 optional) to obtain

[0125] 5. By Perform steps (2) and (3) to obtain the K value for the next round.

[0126] 6. Calculate and compare Ntest ​​items. Find one of them The smallest set of K values As the K value for the next round, As the next round

[0127] 7. Repeat steps 5 and 6 until the second correction value of the phase equilibrium parameter converges. At this point, output the gas phase composition, liquid phase composition, and gas phase fraction as the calculation results.

[0128] As can be seen from the above technical solution, this embodiment provides an isothermal and isobaric flash evaporation calculation method. This method is applied to electronic equipment. Specifically, it involves obtaining multiple system parameters of a non-ideal system, estimating the phase equilibrium constant of the non-ideal system to obtain an initial value of the phase equilibrium constant; based on a gas-liquid two-phase flash evaporation model, the initial value, and multiple system parameters, analyzing whether the feed of the non-ideal system has liquid-phase stability, and correcting the initial value to obtain a first corrected value of the phase equilibrium parameter; if the feed does not have liquid-phase stability, analyzing whether the feed has gas-phase stability based on the gas-liquid two-phase flash evaporation model, the first corrected value, and multiple system parameters, and correcting the first corrected value to obtain a second corrected value of the phase equilibrium parameter; if the feed does not have gas-phase stability, performing gas-liquid two-phase flash evaporation calculation on the feed based on the gas-liquid two-phase flash evaporation model, the second corrected value, and multiple system parameters, obtaining and outputting the calculation result. Compared with the prior art, this application uses a rigorous thermodynamic model to determine the phase state, thereby making the calculation result closer to the actual situation, and enabling the production control system to implement stable control of the chemical production process based on the calculation result.

[0129] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0130] Although the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. In certain environments, multitasking and parallel processing may be advantageous.

[0131] It should be understood that the steps described in the method embodiments of this disclosure may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this disclosure is not limited in this respect.

[0132] Computer program code for performing the operations of this disclosure can be written in one or more programming languages ​​or a combination thereof, including but not limited to object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer.

[0133] Figure 5 This is a block diagram of an isothermal and isobaric flash evaporation calculation device according to an embodiment of this application.

[0134] like Figure 5 As shown, the isothermal and isobaric flash evaporation calculation device provided in this embodiment is applied to an electronic device for performing flash evaporation calculations on non-ideal systems. This electronic device can be understood as a computer, server, cloud platform, or controller or embedded device of a chemical production system with data calculation and information processing capabilities. The calculation device includes a parameter acquisition module 10, a constant estimation module 20, a liquid phase stability testing module 30, a gas phase stability testing module 40, and a flash evaporation calculation execution module 50.

[0135] The parameter acquisition module is used to acquire multiple system parameters for non-ideal systems.

[0136] The system parameters include, but are not limited to, the composition of the system feed, as well as the system temperature and system pressure.

[0137] The constant estimation module is used to estimate the phase equilibrium parameter K of a non-ideal system.

[0138] The phase equilibrium parameter K of the non-ideal system is obtained through calculations performed according to preset steps. There are two methods for estimating the initial value of the phase equilibrium constant K:

[0139] ①Wilson correlation;

[0140] K i =exp(5.373*(1+ω) i )*(1-1 / Tr i ) / Pr i

[0141] In the formula, ω i Tr is the eccentricity factor that makes up i; i The comparison temperature of component i; Pri The comparative pressure that makes up i.

[0142] ② Assuming an ideal gas and ideal solution model, calculate the K value using the saturated vapor pressure method provided by the process simulation software.

[0143] K i =P i s / P

[0144] In the formula, P i s Let be the saturated vapor pressure of component i; P is the system pressure.

[0145] The approach adopted in this invention is to prioritize method ①, and to use method ② if method ① cannot be used due to missing parameters.

[0146] The liquid phase stability test module is used to determine whether the feed of a non-ideal system has liquid phase stability.

[0147] Based on a gas-liquid two-phase flash evaporation model, the initial value of the phase equilibrium constant, and the aforementioned system parameters, the analysis examines whether the feed to a non-ideal system exhibits liquid-phase stability. If liquid-phase stability is found, the analysis results are output, and the initial value of the phase equilibrium constant is corrected to obtain the first corrected value of the phase equilibrium parameters. The specific process is as follows: Figure 2 As shown:

[0148] 1. Composition of the feed z i The first liquid phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0149] 2. Calculate the virtual gas phase composition Y i =z i K i ;

[0150] 3. Calculate the sum of the virtual gas phase compositions: SumY = ∑Y i ;

[0151] 4. Calculate the normalized gas phase composition y i =Y i / SumY;

[0152] 5. Composed of normalized gas phase y i The first gas phase fugacity coefficient was obtained by calculating the system temperature T and system pressure.

[0153] 6. Update phase equilibrium constants

[0154] 7. Repeat steps 2 to 6 until the initial values ​​of the phase equilibrium parameters mentioned above converge.

[0155] During the liquid phase stability test, when the above phase equilibrium parameters converge, if SumY<=0, the feed is liquid phase and the virtual gas phase composition is output; if SumY>0, it indicates that there is no liquid phase stability, and the next step of gas phase stability test is performed.

[0156] The gas phase stability test module is used to determine whether a non-ideal system feed has gas phase stability.

[0157] If the feed does not have liquid-phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value, and multiple system parameters, the gas-phase stability of the feed is analyzed. If gas-phase stability is achieved, the analysis results are output, and the first correction value is corrected to obtain the second correction value for the phase equilibrium parameters. Figure 3 As shown.

[0158] 1. Composed of feed components z i The second gas phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0159] 2. Calculate the virtual liquid phase composition X i =z i / K i ;

[0160] 3. Calculate the sum of the virtual liquid phase compositions: SumX = ∑X i ;

[0161] 4. Calculate the normalized liquid phase composition x i =X i / SumX;

[0162] 5. Composed of normalized liquid phase x i The second liquid phase fugacity coefficient is obtained by calculating the system temperature T and system pressure P.

[0163] 6. Calculate the reference value of the phase equilibrium constant for the next round.

[0164] 7. Use the batch trial method to test K in this round. i to The average is divided into N test Segments (2-20 optional) are obtained

[0165] 8. By Perform steps 2-6 to obtain the K value for the next round.

[0166] 9. Calculate and compare Find one of them The smallest set of K values As the K value for the next round, As the next round

[0167] 10. Repeat steps 7 to 9 until the first correction value of the phase equilibrium parameters mentioned above converges.

[0168] During the gas phase stability test, when the first correction value converges, if SumX <= 0, the feed is in the gas phase and the virtual liquid phase composition is output; if SumX > 0, it indicates that the feed is not a pure gas phase, and the next step of gas-liquid two-phase flash evaporation calculation is performed.

[0169] The flash calculation execution module is used to perform gas-liquid two-phase flash calculations on the feed.

[0170] If the feed lacks gas-phase stability, gas-liquid two-phase flash evaporation calculations are performed on the feed based on the second correction value of the gas-liquid two-phase flash evaporation model and multiple system parameters. The calculation results are then obtained and output, such as... Figure 4 As shown.

[0171] 1. The K value output from the gas-phase stability test module is input into the gas-liquid two-phase flash evaporation module as the initial value; 2. Determine whether the K value satisfies the flash evaporation problem. If not, adjust the K value as follows:

[0172] 2-1. Calculate SumX = Σz from the value of K. i / K i And SumY=∑z i *K i If both SumX and SumY are greater than 1, no adjustment is needed, and proceed directly to step (3); otherwise, skip to step (2.2).

[0173] 2-2. If SumX < 1, then the coefficient C = SumX 0.9 *SumY -0.1 If SumY < 1, then the coefficient C = SumX 0.1 *SumY -0.9 ;

[0174] 2-3. Adjust the K value, K i =K i *C;

[0175] 3. Solve the Rachford-Rice equation using the trial-and-error method to obtain the reference values ​​for the next iteration.

[0176] 4. Use the batch testing method to test K in this round. i to Divide the average into Ntest ​​segments (2 to 20 optional) to obtain

[0177] 5. By Perform steps (2) and (3) to obtain the K value for the next round.

[0178] 6. Calculate and compare Ntest ​​items. Find one of them The smallest set of K values As the K value for the next round, As the next round

[0179] 7. Repeat steps 5 and 6 until the second correction value of the phase equilibrium parameter converges. At this point, output the gas phase composition, liquid phase composition, and gas phase fraction as the calculation results.

[0180] As can be seen from the above technical solution, this embodiment provides an isothermal and isobaric flash evaporation calculation device. This method is applied to electronic equipment, specifically by acquiring multiple system parameters of a non-ideal system, estimating the phase equilibrium constant of the non-ideal system to obtain an initial value of the phase equilibrium constant; based on a gas-liquid two-phase flash evaporation model, the initial value, and multiple system parameters, analyzing whether the feed of the non-ideal system has liquid-phase stability, and correcting the initial value to obtain a first corrected value of the phase equilibrium parameter; if the feed does not have liquid-phase stability, analyzing whether the feed has gas-phase stability based on the gas-liquid two-phase flash evaporation model, the first corrected value, and multiple system parameters, and correcting the first corrected value to obtain a second corrected value of the phase equilibrium parameter; if the feed does not have gas-phase stability, performing gas-liquid two-phase flash evaporation calculation on the feed based on the gas-liquid two-phase flash evaporation model, the second corrected value, and multiple system parameters, obtaining and outputting the calculation result. Compared to existing technologies, this application uses a rigorous thermodynamic model to determine the phase state, thereby enabling the calculation results to be closer to the actual situation, and thus allowing the production control system to implement stable control of the chemical production process based on the calculation results.

[0181] The units described in the embodiments of this disclosure can be implemented in software or in hardware. The name of a unit does not necessarily limit the unit itself; for example, the first acquisition unit can also be described as "a unit that acquires at least two Internet Protocol addresses".

[0182] The functions described above in this document can be performed, at least in part, by one or more hardware logic components. For example, exemplary types of hardware logic components that can be used, without limitation, include: Field Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application Standard Products (ASSPs), System-on-Chip (SoCs), Complex Programmable Logic Devices (CPLDs), and so on.

[0183] Figure 6 This is a block diagram of an electronic device according to an embodiment of this application.

[0184] The following is for reference. Figure 6 This document illustrates a structural diagram suitable for implementing the electronic device in the embodiments of this disclosure. The terminal device in the embodiments of this disclosure may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. This electronic device is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this disclosure.

[0185] The electronic device may include a processing unit (e.g., a central processing unit, a graphics processing unit, etc.) 601, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from an input device 606 into a random access memory (RAM) 603. The RAM also stores various programs and data required for the operation of the electronic device. The processing unit, ROM, and RAM are interconnected via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0186] Typically, the following devices can be connected to the I / O interface: input devices including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 608 including, for example, magnetic tapes, hard disks, etc.; and communication devices 609. Communication device 609 allows the electronic device to communicate wirelessly or wiredly with other devices to exchange data. Although electronic devices with various devices are shown in the figures, it should be understood that it is not required to implement or possess all of the devices shown. More or fewer devices may be implemented or possessed alternatively.

[0187] This application also provides an embodiment of a computer-readable storage medium.

[0188] The aforementioned computer-readable storage medium is applied to an electronic device and carries one or more computer programs. When the electronic device executes these programs, it causes the device to estimate the phase equilibrium constant of the non-ideal system to obtain multiple system parameters of the non-ideal system, thus obtaining an initial value for the phase equilibrium constant. Based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters, it analyzes whether the feed of the non-ideal system has liquid-phase stability and corrects the initial value to obtain a first corrected value for the phase equilibrium parameter. If the feed does not have liquid-phase stability, it analyzes whether the feed has gas-phase stability based on the gas-liquid two-phase flash evaporation model, the first corrected value, and the multiple system parameters, and corrects the first corrected value to obtain a second corrected value for the phase equilibrium parameter. If the feed does not have gas-phase stability, it performs gas-liquid two-phase flash evaporation calculations on the feed based on the gas-liquid two-phase flash evaporation model, the second corrected value, and the multiple system parameters, and obtains and outputs the calculation results. Compared with existing technologies, this application uses a rigorous thermodynamic model to determine the phase state, which makes the calculation results closer to the actual situation, and enables the production control system to implement stable control of the chemical production process based on the calculation results.

[0189] It should be noted that the computer-readable medium described above in this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0190] In this disclosure, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device. In this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (radio frequency), etc., or any suitable combination thereof.

[0191] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0192] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0193] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0194] The technical solution provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. An isothermal and isobaric flash evaporation calculation method, applied to electronic equipment, for calculating the composition and quantity of gas and liquid phases after phase separation in a non-ideal system, characterized in that... The isothermal and isobaric flash evaporation calculation method includes the following steps: Obtain multiple system parameters of the non-ideal system, including the composition of the feed, as well as the system temperature and system pressure of the non-ideal system; The phase equilibrium constant of the non-ideal system is estimated to obtain an initial value for the phase equilibrium constant; Based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters, the analysis is performed to determine whether the feed of the non-ideal system has liquid phase stability. If it has liquid phase stability, the analysis results are output, and the initial value is corrected to obtain the first corrected value of the phase equilibrium constant. If the feed does not have liquid phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value and the multiple system parameters, the analysis is performed to determine whether the feed has gas phase stability. If it has gas phase stability, the analysis result is output, and the first correction value is corrected to obtain the second correction value of the phase equilibrium constant. If the feed does not have gas phase stability, then gas-liquid two-phase flash evaporation calculation is performed on the feed based on the gas-liquid two-phase flash evaporation model, the second correction value and the multiple system parameters, and the calculation results are obtained and output. The method, based on a gas-liquid two-phase flash evaporation model, the initial values, and the multiple system parameters, analyzes whether the feed of the non-ideal system possesses liquid-phase stability. If liquid-phase stability is found, the analysis results are output, and the initial values ​​are corrected to obtain a first corrected value for the phase equilibrium constant. This includes the following steps: Calculate the first liquid phase fugacity coefficient based on the composition, the system temperature, and the system pressure; The virtual gas phase composition is calculated based on the initial value of the phase equilibrium constant; The sum of the virtual gas phase compositions is calculated based on the aforementioned virtual gas phase compositions; The normalized gas phase composition is calculated based on the virtual gas phase composition and the sum of the virtual gas phase compositions; The first gas phase fugacity coefficient is calculated based on the normalized gas phase composition, the system temperature, and the system pressure. The initial value of the phase equilibrium constant is updated based on the first liquid phase fugacity coefficient and the first gas phase fugacity coefficient; The initial value is judged to determine whether it converges. If it does not converge, the process returns to the step of calculating the virtual gas phase composition based on the initial value of the phase equilibrium constant. If it converges, the subsequent operation is performed, and the final initial value is used as the first correction value. The feed is judged based on the sum of the virtual gas phase composition. If the sum of the virtual gas phase composition is less than or equal to zero, the feed has liquid phase stability; otherwise, it does not have liquid phase stability. If the feed does not have liquid-phase stability, then based on the gas-liquid two-phase flash evaporation model, the first correction value, and the multiple system parameters, the analysis of whether the feed has gas-phase stability is performed. If it has gas-phase stability, the analysis result is output, and the first correction value is corrected to obtain a second correction value for the phase equilibrium constant, including the following steps: Calculate the second gas phase fugacity coefficient based on the composition, the system temperature, and the system pressure; The virtual liquid phase composition is calculated based on the first correction value of the phase equilibrium constant; The sum of the virtual liquid phase compositions is calculated based on the aforementioned virtual liquid phase composition; The normalized liquid phase composition is calculated based on the virtual liquid phase composition and the sum of the virtual liquid phase compositions; The second liquid phase fugacity coefficient is calculated based on the normalized liquid phase composition, the system temperature, and the system pressure. The first correction value of the phase equilibrium constant is updated based on the second liquid phase fugacity coefficient and the second gas phase fugacity coefficient; If the first correction value does not converge, the process returns to the step of calculating the virtual liquid phase composition based on the first correction value of the phase equilibrium constant. If the process converges, the subsequent operation is performed, and the final first correction value is used as the second correction value. The feed is judged based on the sum of the virtual liquid phase composition. If the sum of the virtual liquid phase composition is less than or equal to zero, the feed has gas phase stability; otherwise, it does not have gas phase stability.

2. The isothermal and isobaric flash evaporation calculation method as described in claim 1, characterized in that, The gas-liquid two-phase flash evaporation model includes the mass conservation equation, phase equilibrium equation, composition normalization equation, and heat conservation equation.

3. The isothermal and isobaric flash evaporation calculation method as described in claim 2, characterized in that, The heat conservation equation is the Rachford-Rice equation.

4. The isothermal and isobaric flash evaporation calculation method as described in claim 1, characterized in that, If the feed does not have gas-phase stability, then based on the second correction value of the gas-liquid two-phase flash evaporation model and the multiple system parameters, a gas-liquid two-phase flash evaporation calculation is performed on the feed to obtain and output the calculation results, including the following steps: Determine whether the second correction value makes the flash evaporation problem valid; If the aforementioned flash evaporation problem does not apply, then the second correction value is adjusted; If the flash evaporation problem holds true, then the second correction value is iteratively processed based on the heat conservation equation to obtain an iterative reference value; The range between the second correction value and the iterative reference value is divided into multiple numerical segments, and then based on the constraint value corresponding to each numerical segment, the process continues until the constraint value converges. When the constraint value converges, the calculation result is output.

5. The isothermal and isobaric flash evaporation calculation method as described in claim 4, characterized in that, If the flash evaporation problem does not exist, the second correction value is adjusted, including the following steps: The sum of the virtual gas phase composition and the sum of the virtual liquid phase composition of the feed are calculated based on the second correction value; The second correction value is adjusted based on the sum of the virtual gas phase composition and the sum of the virtual liquid phase composition.

6. An isothermal and isobaric flash evaporation calculation device, applied in electronic equipment, for calculating the composition and quantity of gas and liquid phases after phase separation in a non-ideal system, characterized in that... The isothermal and isobaric flash evaporation calculation device includes: The parameter acquisition module is configured to acquire multiple system parameters of the non-ideal system, including the composition of the feed, as well as the system temperature and system pressure of the non-ideal system; The constant estimation module is configured to estimate the phase equilibrium constant of the non-ideal system to obtain an initial value of the phase equilibrium constant; The liquid phase stability test module is configured to analyze whether the feed of the non-ideal system has liquid phase stability based on the gas-liquid two-phase flash evaporation model, the initial value, and the multiple system parameters. If it has liquid phase stability, the analysis result is output, and the initial value is corrected to obtain the first corrected value of the phase equilibrium constant. The gas phase stability testing module is configured to analyze whether the feed has gas phase stability based on the gas-liquid two-phase flash evaporation model, the first correction value, and the multiple system parameters if the feed does not have liquid phase stability. If the feed has gas phase stability, the analysis result is output, and the first correction value is corrected to obtain the second correction value of the phase equilibrium constant. The flash calculation execution module is configured to perform gas-liquid two-phase flash calculation on the feed based on the gas-liquid two-phase flash model, the second correction value, and the multiple system parameters if the feed does not have gas-phase stability, and obtain and output the calculation results. The liquid phase stability testing module is specifically configured to: calculate a first liquid phase fugacity coefficient based on the composition, system temperature, and system pressure; calculate a virtual gas phase composition based on an initial value of the phase equilibrium constant; calculate the sum of virtual gas phase compositions based on the virtual gas phase compositions; calculate a normalized gas phase composition based on the virtual gas phase compositions and the sum of the virtual gas phase compositions; calculate a first gas phase fugacity coefficient based on the normalized gas phase composition, system temperature, and system pressure; update the initial value of the phase equilibrium constant based on the first liquid phase fugacity coefficient and the first gas phase fugacity coefficient; determine whether the initial value has converged; if it has not converged, return to the step of calculating the virtual gas phase composition based on the initial value of the phase equilibrium constant; if it has converged, perform subsequent operations and use the final initial value as the first correction value; and determine the feed based on the sum of the virtual gas phase compositions; if the sum of the virtual gas phase compositions is less than or equal to zero, the feed has liquid phase stability; otherwise, it does not have liquid phase stability. The gas phase stability testing module is specifically configured to: calculate a second gas phase fugacity coefficient based on the composition, system temperature, and system pressure; calculate a virtual liquid phase composition based on a first correction value of the phase equilibrium constant; calculate the sum of virtual liquid phase compositions based on the virtual liquid phase compositions; calculate a normalized liquid phase composition based on the virtual liquid phase compositions and the sum of the virtual liquid phase compositions; calculate a second liquid phase fugacity coefficient based on the normalized liquid phase composition, system temperature, and system pressure; update the first correction value of the phase equilibrium constant based on the second liquid phase fugacity coefficient and the second gas phase fugacity coefficient; determine whether the first correction value has converged; if it has not converged, return to the step of calculating the virtual liquid phase composition based on the first correction value of the phase equilibrium constant; if it has converged, perform subsequent operations and use the final first correction value as the second correction value; and determine the feed based on the sum of the virtual liquid phase compositions; if the sum of the virtual liquid phase compositions is less than or equal to zero, the feed has gas phase stability; otherwise, it does not have gas phase stability.

7. An electronic device, characterized in that, The electronic device includes at least one processor and a memory connected to the processor, wherein: The memory is used to store computer programs or instructions; The processor is used to execute the computer program or instructions to enable the electronic device to implement the isothermal and isobaric flash evaporation calculation method as described in any one of claims 1 to 5.

8. A computer-readable storage medium for use in electronic devices, characterized in that, The storage medium carries one or more computer programs that can be executed by the electronic device, thereby enabling the electronic device to implement the isothermal and isobaric flash evaporation calculation method as described in any one of claims 1 to 5.

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