Physical property calculation method for real-time simulation of nuclear thermal fluid system

Abstract

The invention belongs to the technical field of real-time simulation of nuclear power, aims to solve the problems of calculation oscillation, abnormity and even failure caused by insufficient precision of traditional physical property calculation, and discloses a physical property calculation method for real-time simulation of a nuclear thermal fluid system, which comprises the following steps of: establishing a data matrix table covering all physical property intervals of fluid; adding the obtained one-dimensional data list and the two-dimensional data matrix table into a real-time simulation platform database, establishing a physical property region boundary positioning table, adding the boundary positioning table into the real-time simulation platform database, performing composite interpolation on the data matrix table of all physical property regions, and correcting interpolation data by adopting the physical property region boundary positioning table to obtain a real-time simulation result. And the interpolation process is encoded on a real-time simulation platform to form a dynamic link library to be called by a simulation tool of the platform, so that efficient and high-precision physical property calculation of the nuclear thermal fluid is realized.

Description

Technical Field

[0001] The present application belongs to the field of nuclear power real-time simulation technology, and in particular, relates to a physical property calculation method for real-time simulation of nuclear thermal fluid systems. Background Art

[0002] The real-time simulation technology of nuclear thermal fluid system can calculate the operating characteristics of the primary and secondary thermal systems of nuclear power plants in real time and accurately. It is an important means to support the training of nuclear power plant operators, design improvements, and verification of changes in operating procedures. This technology uses the lumped parameter method to divide the thermal fluid system into a control body with volume characteristics and a connecting pipe with flow characteristics, and establishes mass and energy conservation simulations for the control body and momentum conservation equations for the connecting pipe. In order to make the equation closed, physical property calculations must be used to close a large number of pressure, density, viscosity, temperature, specific enthalpy and other related relationships in the equation. Therefore, physical property calculations directly affect the accuracy and efficiency of the simulation.

[0003] The fluids of traditional pressurized water reactors are water and steam, and the working fluid state only involves two easily distinguishable physical property intervals: the supercooled zone and the saturated zone. Therefore, in the real-time simulation of nuclear power plants, the physical property calculation of the fluid working fluid is achieved by directly establishing a physical property data table for linear interpolation.

[0004] However, with the rapid development of reactor design, more advanced nuclear energy system designs have been proposed, and the types of working fluids and the complexity of working fluid operating states have increased dramatically. From the initial second-generation pressurized water reactor to the third-generation reactor, and then to the fast reactor, molten salt reactor and high-temperature gas-cooled reactor design with fourth-generation characteristics, the types of nuclear thermal working fluids have been continuously expanded and the state changes of working fluids have become more drastic. In addition to water and steam, new flowing working fluids include liquid and steam sodium, molten salt fluids, etc. At the same time, the working fluid state is also more complex, and more physical property ranges are involved. On the one hand, there are huge differences in the rate of change of physical property parameters in different physical property ranges, especially at the boundaries of the ranges. On the other hand, the state changes of the fluid in the power plant system are more complex and frequently cross physical property zones.

[0005] The rate of change of physical properties of different working fluids varies greatly, especially at the boundaries of physical property intervals, where mutations are common. In these mutation areas, the error of the traditional physical property table interpolation method can reach 10%, which is difficult to meet the simulation accuracy requirements of nuclear thermal fluids, and even the errors may lead to serious consequences such as failure of simulation calculations of nuclear thermal fluid systems. For example, when the secondary circuit steam of a fast reactor or a high temperature reactor crosses the boundary of the saturated zone or the superheated zone, the physical property calculation error often causes an abnormal step change in the steam temperature. Summary of the invention

[0006] The purpose of this application is to provide a physical property calculation method for real-time simulation of nuclear thermal fluid systems, to achieve efficient and high-precision physical property calculations for nuclear thermal fluids, and to solve the problem of calculation oscillations, anomalies, or even failures caused by insufficient accuracy of traditional physical property calculations.

[0007] In order to achieve the above objectives, this application provides the following technical solutions:

[0008] The present application provides a physical property calculation method for real-time simulation of a nuclear thermal fluid system, comprising:

[0009] S1: Establish a data matrix table M covering all physical property ranges of the fluid;

[0010] S2: Add the one-dimensional data list and two-dimensional data matrix table obtained in S1 to the real-time simulation platform database and make them part of the platform native data for retrieval by all platform tools;

[0011] S3: Establishing a physical property zone boundary positioning table;

[0012] S4: Add the boundary location table in S3 to the real-time simulation platform database and make it part of the platform native data for all platform tools to retrieve;

[0013] S5: performing composite interpolation on the data matrix table M of all physical property intervals;

[0014] S6: Use the physical property zone boundary positioning table to correct the interpolation data of S5 and perform composite interpolation calculation;

[0015] S7: Encode the interpolation process of S5 and S6 on the real-time simulation platform to form a dynamic link library for the simulation tool of the platform to call.

[0016] In some embodiments, step 1 specifically includes:

[0017] S1.1: Determine the value range of the physical property parameters in the data matrix table M;

[0018] S1.2: Determine the type of data matrix table M;

[0019] S1.3: Calculate the one-dimensional data list of input parameters;

[0020] S1.4: Calculate the two-dimensional data matrix of the output parameters.

[0021] In some embodiments, the physical property parameters involved in the simulation calculation of the nuclear thermal fluid system include pressure, temperature, specific enthalpy, viscosity, thermal conductivity, specific heat, Prandtl number, density, specific entropy, and gas constant.

[0022] In some embodiments, in S1.4, the output parameter values ​​are calculated using the standard physical property calculation formula according to the data list in S1.3, and the two-dimensional data matrix is ​​filled in sequence until all types of data matrix tables in S1.2 are generated.

[0023] In some embodiments, step 3 specifically includes:

[0024] S3.1: Determine the type of boundary positioning table, including the boundary positioning table of the supercooling zone and the saturated zone, the boundary positioning table of the superheating zone and the saturated zone, the boundary positioning table of the supercooling zone and the critical zone, and the boundary positioning table of the superheating zone and the critical zone;

[0025] S3.2: Create a boundary location table for each type of table in S1.

[0026] In some embodiments, the specific enthalpy and temperature values ​​at the boundary of the supercooled zone and the saturated zone are calculated using the standard physical property calculation formula according to the pressure data list, and the boundary specific enthalpy data table corresponding to the pressure and the boundary temperature data table corresponding to the pressure are obtained; then, the pressure and temperature values ​​at the boundary of the supercooled zone and the saturated zone are calculated using the standard physical property calculation formula according to the specific enthalpy data list, and the boundary pressure data table corresponding to the specific enthalpy and the boundary temperature data table corresponding to the specific enthalpy are obtained. Other types are processed in the same way, for example, querying specific enthalpy according to pressure and temperature, querying dynamic viscosity according to pressure and temperature, querying thermal conductivity according to pressure and temperature, and querying constant pressure specific heat according to pressure and temperature.

[0027] In some embodiments, step 5 specifically includes:

[0028] S5.1: On the x-axis, according to the working fluid state m, the interpolation index i and i+1 in the one-dimensional data list X of the x-axis input parameter are calculated, and the state parameter value is greater than the element value at the array position i and less than the element value at the i+1 position;

[0029] S5.2: Obtain the interpolation index j and j+1 of the fluid working medium state parameter n in the y-axis input parameter array Y;

[0030] S5.3: Combine the index numbers to obtain interpolation elements M(i,j), M(i+1,j), M(i,j+1), and M(i+1,j+1).

[0031] In some embodiments, step 6 specifically includes:

[0032] S6.1: Correct the interpolation points in the x-axis direction;

[0033] S6.2: perform linear interpolation in the x-axis direction;

[0034] For M(i,j) and M(i+1,j) data points:

[0035] If the interpolation points after correction are still M(i,j) and M(i+1,j), the interpolation formula is:

[0036]

[0037] If the correction is M(i,j) and the interface value mm, the interpolation formula is:

[0038]

[0039] If the correction is to the interface value mm and M(i+1,j), the interpolation formula is:

[0040]

[0041] With M j Similarly, for the data points M(i,j+1) and M(i+1,j+1), we can interpolate to get M j+1 ;

[0042] S6.3: Correct the interpolation points in the y-axis direction;

[0043] S6.4: Perform linear interpolation in the y-axis direction to obtain the target physical property parameter M corresponding to the working fluid in the m and n states m,n ,include:

[0044] If after correction, the interpolation point is still M j and M j+1 , the interpolation formula is:

[0045]

[0046] If after correction, the interpolation point is M j And the interface value nn, the interpolation formula is:

[0047]

[0048] If after correction, the interpolation points are still the interface values ​​nn and M j+1 , the interpolation formula is:

[0049]

[0050] In some embodiments, in S6.1, it is determined whether adjacent interpolation points in the x-axis direction cross the boundary line. If so, the interpolation points are updated using boundary data retrieved from the physical property zone boundary positioning table, including:

[0051] For the data points M(i,j) and M(i+1,j) on the x-axis, the corresponding y-axis input parameter value Y(j);

[0052] The interface value xx corresponding to the x-axis input parameter is calculated from the boundary positioning table according to the Y(j) value using the linear interpolation method;

[0053] If X(i) < xx < X(i + 1), it indicates that the data points cross the dividing line in the x-axis direction and the interpolation points need to be updated. If the interface value xx > the known state point m of the working fluid, then use the interface value xx to update the right interpolation point M(i, j + 1). If the interface value xx < the known state point m of the working fluid, then use mm to replace the left interpolation point M(i, j).

[0054] If xx < X(i) or xx > X(i + 1), it is determined that the data points in the x-axis direction do not cross the dividing line and the interpolation points do not need to be updated.

[0055] In some embodiments, S6.3 includes:

[0056] The interpolation points in the y-axis direction are M j and M j+1 , and the interface value yy corresponding to the y-axis input parameter is calculated by the boundary location table according to the value of the working fluid state parameter m using the linear interpolation method.

[0057] If Y(i) < yy < Y(i + 1), it indicates that the data points cross the dividing line in the y-axis direction and the interpolation points need to be updated. If the interface value yy > the known state point n of the working fluid, then use the interface value yy to update the upper interpolation point M j+1 ; if the interface value yy < the known state point n of the working fluid, then use nn to replace the lower interpolation element M j ;

[0058] If yy < Y(j) or yy > Y(j + 1), it is determined that the data points in the y-axis direction do not cross the dividing line and the interpolation points do not need to be updated.

[0059] Compared with the prior art, the physical property calculation method provided by this application for real-time simulation of nuclear thermal fluid systems has the following beneficial effects:

[0060] This method has good versatility and scalability, and provides a unified physical property calculation method for all fluid simulation tools in the real-time simulation platform (such as the RINSIM real-time simulation platform). It is not only applicable to common nuclear thermal fluid working media such as water, steam, oil, sodium, molten salt, and non-condensable gases, but also can calculate the physical properties of new flowing working media by updating the physical property data in the real-time simulation platform.

[0061] This method also has the characteristics of high precision. By constructing a two-dimensional data matrix table M covering the entire physical property range of the fluid and a one-dimensional physical property region boundary location table, more three-dimensional distribution characteristics of the physical property parameters are retained. Furthermore, during the composite interpolation process, the boundary location table of the physical property region can be used to accurately identify the position of the dividing line, and the physical property calculation process can be calibrated using the physical property data of the dividing line, avoiding the errors caused by interpolation across the physical property boundary and improving the calculation accuracy.

[0062] In addition, the method of characterizing the three-dimensional physical property distribution by a two-dimensional data matrix table M and a one-dimensional physical property zone boundary positioning table can greatly reduce the amount of data and reduce the demand for storage resources and computing resources. Therefore, this method also has the characteristics of high computing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for the technical description.

[0064] Figure 1 A flow chart of a physical property calculation method for real-time simulation of a nuclear thermal fluid system provided in this application;

[0065] Figure 2 Schematic diagram of the composite interpolation process provided for this application;

[0066] Figure 3 The time consumption distribution diagram for calculating physical properties using the IF97 formula provided in this application;

[0067] Figure 4 Time consumption distribution diagram using physical property table interpolation provided for this application;

[0068] Figure 5 Time consumption distribution diagram of composite interpolation of physical property table provided for this application;

[0069] Figure 6 Error distribution diagram using interpolation of physical property tables provided for this application;

[0070] Figure 7 This is the error distribution diagram of the composite interpolation of the physical property table provided in this application. DETAILED DESCRIPTION

[0071] The following is further explained in detail through specific implementation methods.

[0072] For ease of understanding, this paper briefly introduces the RINSIM simulation platform. The RINSIM real-time simulation platform integrates database management, simulation packages, graphical modeling and debugging, simulation model scheduling and synchronization and other functions. The platform was independently developed by China National Nuclear Corporation Wuhan Nuclear Power Operation Technology Co., Ltd. in 2008 and is currently widely used in the field of nuclear real-time simulation. It should be noted that the present application can be applied to the platform, and a specific implementation method is provided as an example, but as long as it is a real-time simulation platform, the physical property calculation method provided by the present invention can be applied, because it must be equipped with a database, real-time simulation tools, and communication functions of different tools. As long as these functions are available, the physical property calculation method provided by the present invention can be supported. The present application proposes a method for constructing an efficient and high-precision physical property calculation tool for various types of nuclear thermal fluid working fluids such as water, steam, oil, sodium, molten salt, and non-condensable gas on the RINSIM simulation platform.

[0073] like Figure 1 As shown, the present application provides a physical property calculation method for real-time simulation of a nuclear thermal fluid system, comprising:

[0074] S1: Establish a data matrix table M covering all physical property ranges of the fluid. S1 specifically includes:

[0075] S1.1: First determine the value range of the physical property parameters in the data matrix table M.

[0076] The physical parameters involved in the simulation calculation of nuclear thermal fluid system include: pressure, temperature, specific enthalpy, viscosity, thermal conductivity, specific heat, Prandtl number, density, specific entropy, gas constant. The data matrix table M includes the one-dimensional data list and two-dimensional data matrix obtained by S1.3 and S1.4. For example, if z is to be calculated based on x and y, it is necessary to establish a one-dimensional data list of x, a one-dimensional data list of y, and a two-dimensional data matrix of z. Based on these three tables, the z value can be queried based on any x and y values.

[0077] According to the reactor system design, the range of pressure and temperature can be known. Then, other physical property parameters are calculated using standard physical property calculation formulas such as the IF97 formula based on the pressure and temperature values ​​to obtain the range of the remaining parameters.

[0078] S1.2: Then determine the type of data matrix table M. The simulation of the nuclear thermal fluid system requires the use of the following data matrix table:

[0079] 1) Query temperature based on pressure and specific enthalpy;

[0080] 2) Query dynamic viscosity based on pressure and specific enthalpy;

[0081] 3) Query thermal conductivity based on pressure and specific enthalpy;

[0082] 4) Query the specific heat at constant pressure based on pressure and specific enthalpy;

[0083] 5) Query the Prandtl number based on pressure and specific enthalpy;

[0084] 6) Query specific entropy based on pressure and specific enthalpy;

[0085] 7) Query dryness based on pressure and specific enthalpy;

[0086] 8) Query specific enthalpy based on pressure and specific entropy;

[0087] 9) Query specific enthalpy based on pressure and temperature;

[0088] 10) Query dynamic viscosity based on pressure and temperature;

[0089] 11) Query thermal conductivity based on pressure and temperature;

[0090] 12) Query the specific heat at constant pressure based on pressure and temperature;

[0091] 13) Query the Prandtl number based on pressure and temperature;

[0092] 14) Query pressure based on specific enthalpy and density.

[0093] S1.3: Calculate the one-dimensional data list of input parameters. The input parameters in S1.2 include: pressure, temperature, specific enthalpy, specific entropy, and density. Within the value range in S1.1, uniform sampling is performed, and the sampling results are arranged from small to large to form a value list of the input parameters. The number of samples is, for example, in the range of 30-120.

[0094] S1.4: Calculate the two-dimensional data matrix of the output parameters. Calculate the output parameter values ​​using the standard physical property calculation formula based on the data list in S1.3, and fill in the two-dimensional data matrix in sequence until all types of data matrix tables in S1.2 are generated.

[0095] S2: Add the one-dimensional data list in S1.3 and the two-dimensional data matrix table in S1.4 to the database of the existing RINSIM real-time simulation platform, and make them part of the platform's native data for retrieval by all platform tools.

[0096] S3: Establishing a physical property zone boundary positioning table. S3 specifically includes:

[0097] S3.1: First determine the type of boundary location table.

[0098] The nuclear thermal fluid system mainly involves the following physical property intervals: supercooled zone, saturated zone, superheated zone, and critical zone. Therefore, the nuclear thermal fluid system simulation mainly involves the following types of physical property zone boundary positioning lists:

[0099] 1) Boundary location table of supercooled zone and saturated zone;

[0100] 2) Boundary location table of overheating zone and saturation zone;

[0101] 3) Boundary location table of supercooled zone and critical zone;

[0102] 4) Boundary location table of overheating zone and critical zone.

[0103] S3.2: Create a boundary positioning table for each type of table in S1.2.

[0104] Due to too many types, the "Boundary Positioning Table of Supercooling Zone and Saturated Zone" of the "Query Temperature Based on Pressure and Specific Enthalpy" data table in S1.2 is used as an example to illustrate. Similarly, other types of data tables can be obtained. According to the pressure data list in S1.3, the standard physical property calculation formula is used to calculate the specific enthalpy value and temperature value at the "boundary of supercooling zone and saturated zone", and the following are obtained: the boundary specific enthalpy data table corresponding to pressure, and the boundary temperature data table corresponding to pressure. Subsequently, according to the specific enthalpy data list in S1.3, the standard physical property calculation formula is used to calculate the pressure value and temperature value at the "boundary of supercooling zone and saturated zone", and the following are obtained: the boundary pressure data table corresponding to specific enthalpy, and the boundary temperature data table corresponding to specific enthalpy.

[0105] S4: Add the boundary location table in S3.2 to the database of the RINSIM real-time simulation platform and make it part of the platform's native data for retrieval by all platform tools.

[0106] S5: Perform composite interpolation on the data matrix table M of all physical property intervals.

[0107] The composite interpolation process is specifically described by taking the data matrix table M for querying temperature based on pressure and specific enthalpy as an example. The pressure is regarded as the x-axis of the matrix table, and the pressure data list in S1.3 is called X. The specific enthalpy is regarded as the y-axis of the matrix table, and the specific enthalpy data list in S1.3 is called Y, and the temperature is the z-axis. The known pressure state of the working fluid is called m, and the known specific enthalpy state is called n.

[0108] S5.1: On the x-axis, calculate the interpolation index i and i+1 in the one-dimensional data list X of the x-axis input parameter according to the working fluid state m, requiring that the state parameter value is greater than the element value of the array at position i and less than the element value at position i+1.

[0109] S5.2: Similarly, the interpolation indexes j and j+1 of the fluid working medium state parameter n in the y-axis input parameter array Y are obtained.

[0110] S5.3: Combine the index numbers to obtain interpolation elements M(i,j), M(i+1,j), M(i,j+1), and M(i+1,j+1).

[0111] S6: Use the physical property zone boundary positioning table to correct the interpolation data of step S5 and perform composite interpolation calculation.

[0112] Since the rates of change of physical properties in different physical property intervals are different, when the adjacent elements of the data matrix table M in S5 cross the boundary lines of each zone, it will cause obvious errors. The calculation method described in this application uses the physical property zone boundary positioning table to identify the position of the boundary line, and uses the boundary line data and the data matrix table M for composite interpolation to calculate the fluid physical properties. The specific calculation process is as follows:

[0113] S6.1: Correct the interpolation points in the x-axis direction. First, determine whether the adjacent interpolation points in the x-axis direction cross the demarcation line. If they cross the demarcation line, update the interpolation points using the boundary data queried from the physical property region boundary positioning table. Specifically as follows:

[0114] For the data points M(i,j) and M(i + 1,j) in the x-axis direction, the corresponding y-axis input parameter value is Y(j).

[0115] Use the linear interpolation method to calculate the interface value xx corresponding to the x-axis input parameter from the boundary positioning table according to the Y(j) value.

[0116] If X(i) < xx < X(i + 1), it indicates that the data points in the x-axis direction cross the demarcation line, and the interpolation points need to be updated. If the interface value xx > the known state point m of the working fluid, it means that the demarcation line is on the right side of the state point, and update the right interpolation point with the interface value xx. The process of updating the right interpolation point is as follows: Query the boundary positioning table according to the interface value xx to obtain the target parameter boundary value mm, and replace the interpolation element M(i + 1,j) with mm. If the interface value xx < the known state point m of the working fluid, it means that the demarcation line is on the left side of the state point, then replace the left interpolation element M(i,j) with mm.

[0117] If xx < X(i) or xx > X(i + 1), it indicates that the data points in the x-axis direction do not cross the demarcation line at this time, and there is no need to update the interpolation points.

[0118] In the x-axis direction, the processing process of the interpolation points M(i + 1,j) and M(i + 1,j + 1) is the same as above.

[0119] S6.2: Perform linear interpolation in the x-axis direction.

[0120] For the data points M(i,j) and M(i + 1,j):

[0121] If the corrected interpolation points are still M(i,j) and M(i + 1,j), the interpolation formula is:

[0122]

[0123] If it is corrected to M(i,j) and the interface value mm, the interpolation formula is:

[0124]

[0125] If it is corrected to the interface value mm and M(i + 1,j), the interpolation formula is:

[0126]

[0127] Similarly, for the data points M(i,j + 1) and M(i + 1,j + 1), M can be interpolated j+1。

[0128] S6.3: Correct the interpolation points in the y-axis direction.

[0129] The interpolation points in the y-axis direction are M j and M j+1 , first, use the linear interpolation method to calculate the interface value yy corresponding to the y-axis input parameter according to the working fluid state parameter m value from the boundary positioning table.

[0130] If Y(i) < yy < Y(i + 1), it indicates that the data points cross the demarcation line in the y-axis direction, and the interpolation points need to be updated. If the interface value yy > the known state point n of the working fluid, it means that the demarcation line is above the state point. At this time, use the interface value yy to update the upper interpolation point M j+1 . The process of updating the upper interpolation point is as follows: query the boundary positioning table according to the interface value yy to obtain the target parameter value nn, and use nn to replace the interpolation element M j+1 . If the interface value yy < the known state point n of the working fluid, it means that the demarcation line is below the state point. At this time, use nn to replace the lower interpolation element M j .

[0131] If yy < Y(j) or yy > Y(j + 1), it indicates that the data points do not cross the demarcation line in the y-axis direction, and there is no need to update the interpolation points.

[0132] S6.4: Perform linear interpolation in the y-axis direction to obtain the target physical property parameter M corresponding to the working fluid at states m and n m,n . Specifically as follows:

[0133] If after correction, the interpolation points are still M j and M j+1 , the interpolation formula is:

[0134]

[0135] If after correction, the interpolation points are M j and the interface value nn, the interpolation formula is:

[0136]

[0137] If after correction, the interpolation points are still the interface value nn and M j+1 , the interpolation formula is:

[0138]

[0139] S7: Encode the interpolation process of S5 and S6 in the RINSIM real-time simulation platform to form a dynamic link library for the platform's simulation tool to call. When the thermal fluid system simulation calculation tool of the RINSIM real-time simulation platform is running, the working fluid state m, n and the physical property table in the platform database will be input into the dynamic link library, and the calculation results will be returned to the simulation calculation tool after interpolation point correction and composite interpolation.

[0140] Therefore, this application proposes a method for constructing an efficient and high-precision physical property calculation tool for various nuclear thermal fluid working media such as water, steam, oil, sodium, molten salt, and non-condensable gas on the RINSIM real-time simulation platform, providing a unified, efficient and high-precision physical property parameter calculation function for the simulation of the primary and secondary loop thermal fluid systems of nuclear reactors, and solving the problem of calculation oscillation, anomalies, or even failures caused by insufficient accuracy of traditional physical property calculations. For example, the steam systems of fast reactors and high-temperature reactors produce abnormal temperature steps due to physical property calculation errors.

[0141] Example

[0142] Taking water and steam fluids in a high-temperature gas-cooled reactor as the object, in order to more clearly explain the technical solution of the present application, the physical property calculation of "calculating temperature based on pressure and specific enthalpy" is used as an example to illustrate the specific implementation process of the present application.

[0143] S1: Establish a data matrix table M covering all physical property ranges of the fluid.

[0144] S1.1: First, determine the range of the physical property parameters in the table. Referring to the design of high-temperature gas-cooled reactor, the pressure range of water and steam is set to 0.1MPa to 20MPa, and the temperature range is set to 0.1℃ to 1000℃. Then, based on the pressure and temperature values, the standard physical property calculation formula can be used to calculate the range of specific enthalpy from 20kJ / kg to 4000kJ / kg.

[0145] S1.2: Then determine the type of table. This embodiment is only for the data matrix table of "calculating temperature based on pressure and specific enthalpy", and the establishment method of other types of tables is the same as this embodiment.

[0146] S1.3: Calculate the one-dimensional data list of input parameters. The pressure is uniformly sampled in the range of 0.1MPa to 20MPa, the number of samples is 110, and the sampling results are stored in the pressure data list Plist in ascending order. The specific enthalpy is uniformly sampled in the range of 20kJ / kg to 4000kJ / kg, the number of samples is 90, and the sampling results are stored in the specific enthalpy data list Hlist in ascending order.

[0147] S1.4: Calculate the two-dimensional data matrix of the output parameters. Use standard physical property calculation formulas such as the IF97 formula to nest and traverse the lists Plist and Hlist to obtain a 110×90 two-dimensional temperature data matrix Tmatrix.

[0148] S2: Add Plist, Hlist and Tmatrix to the database of the RINSIM real-time simulation platform as part of the platform's native data for retrieval by all platform tools.

[0149] S3. Establish a physical property zone boundary positioning table.

[0150] S3.1: First, determine the type of boundary positioning table. The water and steam fluids in the high-temperature gas-cooled reactor only involve the subcooling zone, saturated zone and superheating zone, so the types of boundary positioning tables required include: boundary positioning tables for subcooling zone and saturated zone, and boundary positioning tables for superheating zone and saturated zone.

[0151] S3.2: For the data matrix table of "calculating temperature based on pressure and specific enthalpy" in S1.2, establish a boundary positioning table. First, establish a data table at the boundary of the supercooled zone and the saturated zone: use the standard physical property formula to calculate the specific enthalpy and temperature of saturated water corresponding to the pressure in Plist one by one, and obtain the pressure-saturated water specific enthalpy table and the pressure-saturated water temperature table. Use the standard physical property formula to calculate the pressure and temperature of saturated water corresponding to the specific enthalpy in Hlist one by one, and obtain the specific enthalpy-saturated water pressure table and the specific enthalpy-saturated water temperature table. Then establish a data table at the boundary of the superheated zone and the saturated zone: use the standard physical property formula to calculate the specific enthalpy and temperature of saturated steam corresponding to the pressure in Plist one by one, and obtain the pressure-saturated steam specific enthalpy table and the pressure-saturated steam temperature table. Use the standard physical property formula to calculate the pressure and temperature of saturated steam corresponding to the specific enthalpy in Hlist one by one, and obtain the specific enthalpy-saturated steam pressure table and the specific enthalpy-saturated steam temperature table.

[0152] S4: Add the 8 boundary location tables in S3.2 to the database of the RINSIM real-time simulation platform and make them part of the platform's native data for retrieval by all platform tools.

[0153] S5: Perform composite interpolation on the data matrix table M of the entire physical property interval. Consider pressure as the x-axis of the data matrix table, specific enthalpy as the y-axis of the data matrix table, and temperature as the z-axis. The known pressure of the fluid working medium is p, and the known specific enthalpy is h.

[0154] S5.1: On the x-axis, calculate the interpolation index i, i+1 in the pressure table Plist according to the fluid pressure p, requiring Plist(i+1)>p>Plist(i).

[0155] S5.2: On the y-axis, calculate the interpolation indices j and j + 1 of the fluid specific enthalpy h in the specific enthalpy table Hlist, with the requirement that Hlist(j + 1) > h > Hlist(j).

[0156] S5.3: After combining the index numbers, it can be seen that the interpolation elements in the temperature table Tmatrix are Tmatrix(i,j), Tmatrix(i + 1,j), Tmatrix(i,j + 1), and Tmatrix(i + 1,j + 1) respectively.

[0157] S6: Use the physical property region boundary positioning table to correct the interpolation data in step S5 and perform composite interpolation calculations. Figure 2 The interpolation process is shown.

[0158] S6.1: Correct the interpolation points in the x-axis direction. First, determine whether the adjacent data points in the x-axis direction cross the demarcation line. If they cross the demarcation line, use the boundary data queried from the physical property region boundary positioning table to update the interpolation points. Specifically as follows:

[0159] For the data points Tmatrix(i,j) and Tmatrix(i + 1,j) in the x-axis direction, the specific enthalpy corresponding to the retrieval number j is Hlist(j).

[0160] Use the linear interpolation method to calculate the saturated water pressure Pliq and saturated steam pressure Pstm corresponding to Hlist(j) from the specific enthalpy - saturated water pressure and specific enthalpy - saturated steam pressure tables according to the specific enthalpy value Hlist(j).

[0161] Assume Pliq > Plist(i + 1), which means that at this time, the pressure direction does not cross the demarcation line between saturated water and subcooled water, and there is no need to update the interpolation points using Pliq. Assume Plist(i) < Pstm < Plist(i + 1), indicating that the data points in the pressure direction cross the demarcation line between saturated steam and superheated steam at this time, and the interpolation points need to be updated. Assume the saturated pressure Pstm > the working fluid pressure p, which means that the saturation point is on the right side of the state point p, and the right-side interpolation points need to be updated using the saturation point. At this time, query the pressure - saturated temperature table according to the saturation value Pstm to obtain the saturated output parameter TT, and use TT to replace the interpolation element Tmatrix(i + 1,j).

[0162] The processing process of the data points Tmatrix(i + 1,j) and Tmatrix(i + 1,j + 1) in the x-axis direction is the same as above. Assume that there is no need to update without crossing the saturation region. After correction in the x-axis direction, the interpolation points become Tmatrix(i,j), TT, Tmatrix(i,j + 1), and Tmatrix(i + 1,j + 1).

[0163] S6.2: Perform linear interpolation in the x-axis direction.

[0164] First, interpolate Tmatrix(i,j) and TT:

[0165]

[0166] Similarly, interpolate Tmatrix(i,j+1) and Tmatrix(i+1,j+1).

[0167]

[0168] S6.3: Correct the data points in the y-direction.

[0169] The interpolation point in the y-axis direction is T j and T j+1 First, the saturated steam specific enthalpy Hstm and the saturated water specific enthalpy Hliq are calculated from the pressure-saturated steam specific enthalpy and pressure-saturated water specific enthalpy tables according to the working fluid pressure p using the linear interpolation method.

[0170] Then, the interface values ​​Hstm and Hliq are used to correct the data points in the y-axis direction. The correction process in the y-axis direction is the same as the correction process in the x-axis direction. Assume that the corrected interpolation point becomes T j and Tstm, where Tstm is calculated by Hstm by looking up the specific enthalpy-saturated steam temperature table.

[0171] S6.4: Perform linear interpolation in the y-axis direction to obtain the temperature value Tout of the working fluid under the pressure p and specific enthalpy h state.

[0172]

[0173] S7: Encode the interpolation process of S5 and S6 in the RINSIM real-time simulation platform to form a dynamic link library for the platform's simulation tool to call. When the thermal fluid system simulation calculation tool of the RINSIM real-time simulation platform is running, the working fluid state m, n and the physical property table in the platform database will be input into the dynamic link library, and the calculation results will be returned to the simulation calculation tool after interpolation point correction and composite interpolation.

[0174] Figures 3 to 5 The calculation time distribution of the IF97 formula, the traditional physical property table interpolation method, and the physical property table composite interpolation method described in this article is shown, in units of ms / 10,000 times. From the results, it can be seen that the calculation time of the traditional physical property table interpolation method is on the order of 0.1 seconds. The calculation time of the physical property table composite interpolation method is slightly increased, on the order of 1 second. However, the calculation time of the formula method is much longer than the other methods, on the order of 10 seconds, and the calculation time of the superheated zone>the supercooled zone>the saturated zone.

[0175] Figure 6 and Figure 7 The calculation error distribution of the traditional physical property table interpolation method and the physical property table composite interpolation method is shown. From the results, it can be seen that the traditional physical property table interpolation method has a very obvious error band near the dividing line, and the maximum error can reach 10%. The average error of the physical property table composite interpolation method is about 0.1%.

[0176] Therefore, compared with the traditional physical property table interpolation method, the method described in the present application can improve the calculation efficiency by 90% and reduce the calculation error by 99%, thereby solving the problem of insufficient accuracy of the traditional physical property table interpolation method and supporting the real-time simulation calculation of new reactor fluid systems including sodium-cooled fast reactors, high-temperature reactors, and supercritical reactors.

[0177] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present application should be covered within the protection scope of the present application.

Claims

1. A physical property calculation method for real-time simulation of nuclear thermal fluid system, characterized in that: include: S1: Establish a data matrix table M covering all physical property ranges of the fluid; S2: Add the one-dimensional data list and two-dimensional data matrix table obtained in S1 to the database of the real-time simulation platform and make them part of the platform's native data for retrieval by all platform tools; S3: Establishing a physical property zone boundary positioning table; S4: Add the boundary location table in S3 to the database of the real-time simulation platform and make it part of the platform's native data for retrieval by all platform tools; S5: performing composite interpolation on the data matrix table M of all physical property intervals; S6: Use the physical property zone boundary positioning table to correct the interpolation data of S5 and perform composite interpolation calculation; S7: Encode the interpolation process of S5 and S6 on the real-time simulation platform to form a dynamic link library for the simulation tool of the platform to call.

2. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 1, characterized in that: Step 1 specifically includes: S1.1: Determine the value range of the physical property parameters in the data matrix table M; S1.2: Determine the type of data matrix table M; S1.3: Calculate the one-dimensional data list of input parameters; S1.4: Calculate the two-dimensional data matrix of the output parameters.

3. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 2, characterized in that: The physical parameters involved in the simulation calculation of nuclear thermal fluid systems include pressure, temperature, specific enthalpy, viscosity, thermal conductivity, specific heat, Prandtl number, density, specific entropy, and gas constant.

4. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 2, characterized in that: In S1.4, the output parameter values ​​are calculated using the standard physical property calculation formula according to the data list in S1.3, and the two-dimensional data matrix is ​​filled in sequence until all types of data matrix tables in S1.2 are generated.

5. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 1, characterized in that: Step 3 specifically includes: S3.1: Determine the type of boundary positioning table, including the boundary positioning table of the supercooling zone and the saturated zone, the boundary positioning table of the superheating zone and the saturated zone, the boundary positioning table of the supercooling zone and the critical zone, and the boundary positioning table of the superheating zone and the critical zone; S3.2: Create a boundary location table for each type of table in S1.

6. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 5, characterized in that: According to the pressure data list, the specific enthalpy and temperature values ​​at the boundary between the supercooled zone and the saturated zone are calculated using the standard physical property calculation formula to obtain the boundary specific enthalpy data table corresponding to the pressure and the boundary temperature data table corresponding to the pressure; then, according to the specific enthalpy data list, the pressure and temperature values ​​at the boundary between the supercooled zone and the saturated zone are calculated using the standard physical property calculation formula to obtain the boundary pressure data table corresponding to the specific enthalpy and the boundary temperature data table corresponding to the specific enthalpy.

7. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 1, characterized in that: Step 5 specifically includes: S5.1: On the x-axis, according to the working fluid state m, the interpolation index i and i+1 in the one-dimensional data list X of the x-axis input parameter are calculated, and the state parameter value is greater than the element value at the array position i and less than the element value at the i+1 position; S5.2: Obtain the interpolation index j and j+1 of the fluid working medium state parameter n in the y-axis input parameter array Y; S5.3: Combine the index numbers to obtain interpolation elements M(i,j), M(i+1,j), M(i,j+1), and M(i+1,j+1).

8. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 1, characterized in that: Step 6 specifically includes: S6.1: Correct the interpolation points in the x-axis direction; S6.2: perform linear interpolation in the x-axis direction; For M(i,j) and M(i+1,j) data points: If the interpolation points after correction are still M(i,j) and M(i+1,j), the interpolation formula is: If the correction is M(i,j) and the interface value mm, the interpolation formula is: If it is corrected to the interface value mm and M(i + 1, j), the interpolation formula is: For M(i,j+1) and M(i+1,j+1) data points, interpolate to get M j+1 ; S6.3: Correct the interpolation points in the y-axis direction; S6.4: Perform linear interpolation in the y-axis direction to obtain the target physical property parameter M corresponding to the working fluid in the m and n states m,n ,include: If after correction, the interpolation point is still M j and M j+1 , the interpolation formula is: If after correction, the interpolation point is M j And the interface value nn, the interpolation formula is: If after correction, the interpolation points are still the interface values ​​nn and M j+1 , the interpolation formula is:

9. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 8, characterized in that: In S6.1, it is judged whether the adjacent interpolation points in the x-axis direction cross the demarcation line. If they cross the demarcation line, the boundary data queried by the physical property region boundary positioning table is used to update the interpolation points, including: For the data points M(i, j) and M(i + 1, j) in the x-axis direction, the corresponding y-axis input parameter value is Y(j); The linear interpolation method is used to calculate the interface value xx corresponding to the x-axis input parameter from the boundary positioning table according to the Y(j) value; If X(i) < xx < X(i + 1), it indicates that the data points in the x-axis direction cross the demarcation line and the interpolation points need to be updated. If the interface value xx > the known state point m of the working fluid, the right interpolation point M(i + 1, j) is updated with the interface value xx; if the interface value xx < the known state point m of the working fluid, the left interpolation point M(i, j) is replaced with mm; If xx < X(i) or xx > X(i + 1), it is judged that the data points in the x-axis direction do not cross the demarcation line and the interpolation points do not need to be updated.

10. The physical property calculation method for real-time simulation of nuclear thermal fluid system according to claim 8, characterized in that: S6.3 includes: The interpolation point in the y-axis direction is M j and M j+1 , the interface value yy corresponding to the y-axis input parameter is calculated from the boundary positioning table according to the working fluid state parameter m value by using the linear interpolation method; If Y(i) < yy < Y(i + 1), it indicates that the data points cross the dividing line in the y-axis direction and the interpolation points need to be updated; if the interface value yy > the known state point n of the working fluid, the upper interpolation point M is updated with the interface value yy j+1 ; if the interface value yy < the known state point n of the working fluid, the lower interpolation element M is replaced with nn j ; If yy < Y(j) or yy > Y(j + 1), it is judged that the data points in the y-axis direction do not cross the demarcation line and the interpolation points do not need to be updated.

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