JP2004337792A - Numerical reaction analysis method allowing for flow state in chemical apparatus, calculation program for executing the method and recording medium with the program recorded thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a numerical reaction analysis method capable of performing reaction analysis allowing for the flow state in a chemical apparatus efficiently and closely to a real phenomenon, and to provide a calculation program for executing the method. <P>SOLUTION: In the numerical reaction analysis method, a three-dimensional fluid model and a compartment model are coupled and solved while interchanging necessary data to each other with respect to the reaction analysis allowing for the flow state in the chemical apparatus. Therein, the three-dimensional fluid model is used for fluid analysis of differential equations dominating flow such as equation of continuity, equation of motion and equation of energy conservation by means of a finite difference method. The compartment model is used for reaction calculation in which the split number of region is reduced to 1/10-1/100 of that in the three-dimensional fluid model without lowering the dimension of an analysis space representing the chemical apparatus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a numerical reaction analysis method for analyzing a reaction analysis in consideration of a flow state in a chemical apparatus more closely to a real phenomenon and efficiently, and a calculation program for executing the method.
[0002]
[Prior art]
As a method of analyzing a perfect mixed flow which is an ideal flow in a chemical apparatus and a non-ideal flow which is not an extrusion flow, there is a computational fluid analysis method. In the field of computational fluid dynamics, a finite difference method is often used to analyze in a time-evolution manner with small steps. That is, the three-dimensional analysis space representing the inside of the chemical apparatus is divided into small regions, and differential equations governing the flow such as a continuous equation, a kinetic equation, and an energy conservation equation are subjected to analysis with respect to the divided areas (for example, , Non-Patent Document 1.).
[0003]
However, in this case, in order to perform a stable and accurate calculation, at least tens of thousands of area divisions are required on a real machine scale, and there is a problem that a calculation load is high. Furthermore, when considering the reaction, a model representing the reaction is incorporated in each of the divided regions, so that the calculation load is further increased.
[0004]
On the other hand, regarding the reaction analysis taking into account the flow state in the chemical device, which is a non-ideal flow with a low calculation load, the three-dimensional analysis space representing the inside of the chemical device is approximated to a one- or two-dimensional analysis space, and several to three or more are obtained. A numerical reaction analysis method using a compartment model such as an inverse mixing tank array model in which each area is represented by several tens of areas, and each area is regarded as a complete mixing tank, and a flow analysis connecting flow between the tanks is given to perform a reaction analysis in consideration of a flow state. (For example, see Non-Patent Document 2).
[0005]
However, in the compartment model, it is necessary to empirically determine the area division, the flow rate between the areas, and in the case of multiphase flow, the volume fraction of the constituent phases, etc., and the apparent density, viscosity, and surface tension accompanying the reaction are further reduced. It is difficult to analyze when the flow state changes.
[0006]
As described above, in the conventional analysis method, the analysis is performed using either a model in which a model representing a reaction is incorporated into the CFD analysis or a compartment model in which the dimension of an analysis space representing the inside of a chemical device is reduced. However, there is a problem that it is difficult to carry out the analysis efficiently because it is close to a real phenomenon.
[0007]
[Non-patent document 1]
Nobuo Shibetsu, Masaaki Suzuki, Misako Ishiguro and Haruo Terasaka, "Computational Fluid Dynamics-Model and Numerical Analysis of Complex Flows", Asakura Shoten Co., Ltd., September 10, 1994, p. 104-196
[0008]
[Non-patent document 2]
Chemical Engineering Society, “Revised Sixth Edition Chemical Engineering Handbook”, Maruzen Co., Ltd., February 25, 1999, p. 628-632
[0009]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a numerical reaction analysis method capable of performing a reaction analysis in consideration of a flow state in a chemical device closer to a real phenomenon, and an efficient analysis, and a method for executing the method. To provide a program.
[0010]
[Means for Solving the Problems]
The present invention does not use any one of a three-dimensional flow model and a compartment model for a reaction analysis in consideration of a flow state in a chemical apparatus, but uses a flow equation such as a continuous equation, a kinetic equation, and an energy conservation equation for a flow. Three-dimensional flow model for fluid analysis of the differential equation governing by the finite difference method. For the reaction, the number of domain divisions is reduced to 1/10 to 100 minutes of the three-dimensional flow model without reducing the dimension of the analysis space representing the inside of the chemical apparatus. This is a numerical response analysis method in which two types of compartment models reduced to one are used in combination. Further, the present invention is a program for executing the analysis method and a medium recording the program.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
In the present invention, first, based on the physical properties of the fluid such as density, viscosity, and surface tension, a continuous equation, a kinetic equation, and an energy conservation equation for each area obtained by dividing the chemical device into tens of thousands of areas. Fluid analysis is performed by a three-dimensional flow model that calculates the differential equation governing the flow by the finite difference method, and in the case of flow, pressure, temperature, and in the case of multiphase flow, physical quantities such as the volume fraction of the phases that compose it are Ask. After the calculation of the flow field is completed, the output data obtained by the three-dimensional flow model is used to reduce the dimension of the analysis space representing the inside of the chemical device to 10 to 100 minutes from the three-dimensional flow model. Data conversion is performed, for example, by averaging, so that it can be used in the compartment model used for the reaction calculation reduced to one.
[0013]
Next, the data necessary for performing reaction calculations such as the converted flow rate, pressure, temperature, and, in the case of a multiphase flow, the volume fraction of the phases constituting the multiphase flow, are used as input data to the compartment model, and the compartment model Hand over to the side and calculate the reaction with the compartment model. After the reaction calculation is completed, the output data such as the concentration, reaction rate, heat of reaction and apparent density, viscosity and surface tension obtained based on them are obtained from the compartment model. Is passed as the input data of the three-dimensional flow model for calculating.
[0014]
In this way, the three-dimensional flow model for calculating the fluid by analyzing the differential equations governing the flow such as the continuous equation, the equation of motion, and the energy conservation equation by the finite difference method, and the number of divided regions is 1/10 to 100 of that of the three-dimensional flow model. While exchanging necessary data between two models of the compartment model used for the reaction calculation, which was reduced to one part, the two models were coupled and solved, and the flow state in the chemical equipment was considered. Perform reaction analysis.
[0015]
If the changes in the apparent density, viscosity, and surface tension obtained based on the concentration, reaction rate, and heat of reaction obtained from the compartment model are sufficiently small and the change in flow accompanying the reaction can be ignored, The numerical response analysis can be terminated by transferring the data once to the compartment model and executing the calculation.
[0016]
Referring to FIG. 1, an example of a calculation program for performing a reaction analysis in consideration of a flow state in a chemical device to which the present invention is applied includes an input device 1, an analysis condition input unit 2, an analysis calculation unit 3, and an analysis result display unit. And a display device 5. Here, the analysis condition input unit 2 includes a region division setting unit 2-1 and an analysis condition setting unit 2-2, and the analysis calculation unit 3 includes a flow state analysis calculation unit 3-1 and a reaction analysis calculation unit 3-2. And A is a file.
[0017]
The analysis condition input unit 2 is a part for the user to set the three-dimensional flow model and the compartment model, the generation conditions of each area division, and the analysis conditions necessary for analysis through the input device 1. The user sets coordinate axes in the x, y, and z directions in the analysis area representing the shape of the chemical apparatus by the area division setting means 2-1, and first obtains the coordinates of each of the divided areas of the three-dimensional flow model using the coordinate axes. . Next, based on the region division performed by the three-dimensional flow model, the regions divided for the three-dimensional flow model are integrated, for example, vertically, horizontally, and so as to reduce the dimension of the analysis space representing the inside of the chemical apparatus. A divided region used in a compartment model in which the number of divided regions is not reduced and the number of divided regions is reduced to one tenth to one hundredth of that of the three-dimensional flow model is generated, and the coordinates of each divided region are obtained.
[0018]
Referring to FIG. 2, regions surrounded by solid lines in the three-dimensional flow model and the compartment model are regions divided to use the three-dimensional flow model and a compartment model that does not reduce the dimension of the analysis space representing the inside of the chemical apparatus, respectively. It is. The region divided for the compartment model that does not reduce the dimension of the analysis space representing the inside of the chemical device is, for example, a region that is divided for the three-dimensional flow model and is integrated in the upper, lower, left, and right directions. In the schematic diagram of the area divided for the compartment model, the area divided for the compartment model is indicated by a solid line, and the area divided for the three-dimensional flow model is indicated by a broken line.
[0019]
In addition, the analysis condition setting means 2-2 allows the user to specify the boundary conditions, initial conditions, time step width Δt, physical properties such as density, viscosity and surface tension necessary for the analysis, and the bubble diameter in the case of gas-liquid multiphase flow. Prepare data such as.
[0020]
The analysis calculation unit 3 is a unit for obtaining a physical quantity using a three-dimensional flow model and a compartment model. The flow state analysis calculation unit 3-1 performs time integration by differentiating a differential equation governing flow such as a continuous equation, a motion equation, and an energy conservation equation, and performs flow integration, flow rate, pressure, temperature, and multiphase flow at a specified time. In the case of (1), this is a part for further calculating a physical quantity such as a volume fraction of a phase constituting the phase. The reaction analysis calculation unit 3-2 performs the time integration of the compartment model used for the reaction calculation using the physical quantity obtained by the flow state analysis calculation unit 3-1 as input data, and performs the concentration, the reaction speed, and the reaction at the designated time. This is a part for calculating heat and physical quantities such as apparent density, viscosity and surface tension obtained based on the heat. Further, when the analysis result indicates the output designated time in the input data, the obtained physical quantity is output to the file A.
[0021]
The analysis result display unit 4 is a unit that reads data of physical quantities in the file A calculated by the analysis calculation unit 3 and displays the data on the display device 5 in the form of a graph or a table.
[0022]
FIG. 3 is a flowchart showing the flow of the analysis processing shown in FIG. 1. Hereinafter, the operation of this embodiment will be described with reference to the drawings.
[0023]
First, the user activates the region division setting means 2-1 of the analysis condition input unit 2 from the input device 1, defines the x, y, and z axes on the analysis region representing the inside of the chemical device and represents the inside of the chemical device. The analysis area is divided. Next, the user activates the analysis condition setting means 2-2 of the analysis condition input unit 2 from the input device 1 to execute physical condition values such as boundary conditions, initial conditions, time step width Δt, density, viscosity and surface tension, and gas-liquid multiphase flow. In the case of, input data necessary for analysis such as bubble diameter is given.
[0024]
When the processing of the analysis condition input unit 2 is completed as described above, the analysis calculation unit 3 starts operating and executes the following processing.
[0025]
S1: Coordinate data of the divided region of the three-dimensional flow model created by the analysis condition input unit 2, physical properties of the fluid such as density, viscosity and surface tension, initial conditions such as flow rate, pressure and temperature, boundary conditions and time interval. The data of Δt is read, time integration of the three-dimensional flow model is performed, and a physical quantity such as a flow rate, a pressure, a temperature, and, in the case of a multiphase flow, a volume fraction of a phase constituting the analysis time t = Δt is obtained.
[0026]
S2: The physical quantities such as the flow rate, the pressure, the temperature, and, in the case of the multiphase flow, the volume fraction of the phases constituting the multiphase flow obtained in S1 are converted as input data of the compartment model.
[0027]
For example, the flow rate on the surface divided for the compartment model, which is the input data of the compartment model, is calculated by integrating the flow rates obtained for each of the divided surfaces of the three-dimensional flow model constituting the compartment model. In the case of the pressure, temperature, and multiphase flow in the region divided for the model, the volume fraction of the constituent phase is further calculated as the value obtained for each of the divided regions of the three-dimensional flow model constituting the flow. It is calculated by taking the average.
[0028]
S3: The coordinate data of the divided area of the compartment model created by the analysis condition input unit 2, the flow rate, the pressure, the temperature obtained in S2 as the input data of the compartment model, and, in the case of the multiphase flow, the volume of the phase constituting it. The data of the physical quantity such as the fraction and the data of the time interval Δt are read, the time integration of the compartment model is performed, and the physical quantity such as the concentration, the reaction speed and the reaction heat at the analysis time t = Δt is obtained.
[0029]
S4: Calculate physical quantities such as apparent density, viscosity and surface tension, which are new input data of the three-dimensional flow model, based on the physical quantities such as the concentration, the reaction rate and the heat of reaction obtained in S3.
[0030]
S5: If the current analysis time is the file output specified time specified by the input data, the flow rate, pressure, temperature, and in the case of a multiphase flow, physical quantities such as the volume fraction, the concentration, and the reaction speed of the constituent phase are filed. Output to A.
[0031]
S6: When the analysis time reaches the time specified by the input data, the control is transferred to the analysis display unit 4.
[0032]
S7: Advance the analysis time and return to S1, using physical quantities such as the flow rate, pressure, temperature, and, in the case of a multiphase flow, the volume fraction of the phase constituting the multiphase flow as initial values for the next calculation. The calculation at the new analysis time is performed in the same manner. That is, the processing of S1 to S6 is repeated to sequentially obtain the value of the (n + 1) th step from the value of the nth step (analysis time t = n × Δt, n = 1, 2,...).
[0033]
The analysis display unit 4 displays graphs and tables based on physical quantity data such as the flow rate, pressure, temperature, and, in the case of a multiphase flow, the volume fraction, concentration, and reaction rate of the phases constituting the multiphase flow, in the analysis display unit 4. It is created and displayed on the display device 5. For example, a streamline at a time designated by the input data and a density contour line of the density are calculated, and the streamline diagram and the contour diagram are displayed.
[0034]
【The invention's effect】
As described above, the present invention relates to a reaction analysis in consideration of a flow state in a chemical device, and relates to a three-dimensional flow model capable of accurately analyzing a flow field, and a reaction having a smaller number of regions than the three-dimensional flow model and having a lower calculation load. Since the two types of compartment models used for the calculation are coupled and solved, it is possible to perform an efficient numerical response analysis closer to a real phenomenon.
[0035]
In addition, it is not necessary to determine them empirically by passing necessary data in terms of physical quantities such as the flow rate from the three-dimensional flow model to the compartment model and, in the case of multiphase flow, the volume fraction of the constituent phases, and solving it. Accurate numerical response analysis is also possible.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a calculation program for performing a reaction analysis in consideration of a flow state in a chemical device to which the present invention is applied.
FIG. 2 is a schematic diagram illustrating an example of region division of a three-dimensional flow model and a compartment model according to the embodiment. FIG. 3 is a flowchart illustrating a processing example of an analysis calculation unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input device 2 ... Analysis condition input part 2-1 ... Area division setting means 2-2 ... Analysis condition setting means 3 ... Analysis calculation part 3-1 ... Flow state analysis calculation part 3-2 ... Reaction analysis calculation part 4 ... Analysis result display section 5 Display device A File

Claims (4)

Regarding the reaction analysis considering the flow state in the chemical device, the necessary data from the data of the flow rate, pressure, temperature, and, in the case of multiphase flow, the volume fraction of the phases constituting it, obtained by the three-dimensional flow model, The three-dimensional flow is characterized in that it is transferred to a compartment model in which the number of area divisions is reduced to one tenth to one-hundredth of the three-dimensional flow model without reducing the dimension of the analysis space representing the inside of the chemical apparatus, and the reaction analysis is performed. A numerical response analysis method that combines two types of models, a model and a compartment model. In the coupling between the three-dimensional flow model and the compartment model, the data of the concentration, reaction rate, heat of reaction, and apparent density, viscosity, and surface tension obtained based on the three-dimensional flow model are further obtained. 2. A numerical response analysis method according to claim 1, further comprising the step of: passing necessary data to each other while exchanging the data between the two models. The coordinate data of the divided area of the three-dimensional flow model, the data of the density, viscosity, and surface tension of the fluid, the initial conditions of the flow rate, the pressure and the temperature, the boundary conditions, and the data of the time step Δt are read, and the time integration of the three-dimensional flow model is performed. Step 1 for determining the flow rate, pressure, temperature, and, in the case of a multiphase flow, the volume fraction of the phases constituting the flow at the analysis time t = Δt,
Step 2 of converting the flow rate, pressure, temperature, and, in the case of a multiphase flow, the volume fraction of the phases constituting the three-dimensional flow model as input data of the compartment model,
In the case of the flow rate, pressure, temperature, and multiphase flow obtained in step 2 as the coordinate data of the divided area of the compartment model and the input data of the compartment model, data of the volume fraction of the phase constituting the multiphase flow and the time interval Δt. And performing a time integration of the compartment model to obtain a concentration, a reaction rate and a heat of reaction at an analysis time t = Δt;
A step 4 of calculating an apparent density, a viscosity and a surface tension, which are new input data of the three-dimensional flow model, based on the concentration, the reaction rate and the reaction heat obtained in the step 3;
The analysis time is advanced and the process returns to the step 1. In the case of the flow rate, pressure, temperature, and multiphase flow obtained in the previous calculation, the volume fraction of the phase constituting the flow is used as an initial value for the next calculation, and a new calculation is performed. A numerical response analysis program for causing a computer to perform calculation at the analysis time in the same manner as described above. A medium on which the program according to claim 3 is recorded.

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