Method for obtaining single-phase fluid hydraulic data of pipe network system lacking measuring points

Abstract

The present invention relates to a method for obtaining the hydraulic data of single-phase fluids in a pipe network system lacking measuring points. By combining Kirchhoff's law with the fluid momentum conservation formula, the unknown resistance coefficients and unknowable variables such as manual valves in the fluid network are transformed into the relationship between pressure and flow through parameter transformation. Then, the coupled relationship formula of this pressure and flow is substituted into the fluid network iteration process for joint iteration. Finally, based on the flow rates at the inlet and outlet, the pressure distribution of the entire fluid network system can be deduced. The present invention is a hydraulic calculation algorithm for single-phase fluids in a pipe network based on fluid network theory and aiming at the lack of measuring points in the actual pipe network system, so as to effectively solve the problem of hydraulic simulation calculation of the pipeline system and improve the accuracy and coverage of pipeline monitoring.

Description

Technical Field

[0001] The invention relates to a method for acquiring hydraulic data of a single-phase fluid in a pipe network system lacking measuring points, and belongs to the technical field of fluid network hydraulics. Background Art

[0002] In actual production and life, pipeline transportation is the most common, widespread and economical mode of transportation. However, in the process of fluid transportation, due to the complexity of the pipeline network, the lack of effective measurement points, and the lack of effective monitoring methods for the fluid inside the pipeline with rapid hydraulic and thermal changes.

[0003] In the field of theoretical research and in precision pipeline systems, the principle of fluid network calculation can accurately calculate pipeline hydraulic data. However, in the actual production process, the internal resistance coefficient of the pipeline and the valve opening and related data of the manual regulating valve are usually unknown, making it difficult to calculate using conventional fluid network theory.

[0004] In recent years, the application of fluid network theory has been continuously expanded and deepened. However, hydraulic calculations for pipeline systems with scarce or rapidly changing hydraulic data measurement points are often unable to be achieved with the help of theoretical calculations. Therefore, there is an urgent need for a method to obtain hydraulic data of fluid networks without measurement points in internal pipeline systems. Summary of the invention

[0005] In order to solve the above problems, the present invention discloses a method for acquiring hydraulic data of a single-phase fluid in a pipe network system lacking measuring points, and the specific technical solution is as follows:

[0006] A method for acquiring hydraulic data of a single-phase fluid in a pipe network system lacking measuring points comprises the following steps:

[0007] Step S1, data input and initialization: input the fluid network topology matrix and the original boundary data of the fluid network, and initialize the input data;

[0008] Step S2, setting the iteration step and solving the pressure matrix: after setting the iteration step, entering the iteration loop, solving the data obtained in step S1 according to the mass conservation formula and the momentum conservation formula, constructing the pressure matrix equation, and solving the pressure matrix using the LU decomposition method;

[0009] Step S3, solving a new internal flow matrix: Substituting the solution data of the pressure matrix obtained in step S2 and the data of step S1 into the streamline momentum equation for solving, and obtaining a new internal flow matrix;

[0010] Step S4, update the internal node density array: According to the internal flow matrix obtained in Step S3, combined with the data in Step S1, substitute them into the mass conservation formula for solution, and then obtain the updated internal node density array;

[0011] Step S5, solve the updated internal node specific enthalpy array: Substitute the internal node density array obtained in Step S4 and the data obtained in Step S1 into the energy conservation formula, construct a specific enthalpy matrix equation, and then use the LU decomposition method to solve the specific enthalpy matrix equation to obtain the updated internal node specific enthalpy array;

[0012] Step S6, adjust the internal flow matrix: Add the internal flow matrix obtained after iteration in Step S3 and the initial internal flow matrix in Step S1 and take the average value to obtain a new internal flow matrix;

[0013] Step S7, update the node pressure array: Update the pressure item by item according to Kirchhoff's law and the Darcy-Weisbach formula;

[0014] Step S8, update the density array and the resistance matrix: Update to obtain a new internal resistance matrix and a boundary resistance matrix;

[0015] Step S9, determine whether the iteration ends: Determine whether the pressure converges. If it converges, end the iteration; if it does not converge, return to Step S2.

[0016] Furthermore, in the above Step S1, the original boundary data of the fluid network includes node temperature data, boundary node flow or pressure data, internal node pipe length and diameter data, and inlet pressure;

[0017] The specific initialization process of the input data is as follows: According to the fluid network topology matrix, vectorize the data of the nodes to be solved and the overall data, and matrixize the streamline data; With the help of the IAPWS steam library, calculate and solve other initial data through the initial pressure and temperature; Finally, obtain 10 groups of vector data, namely the internal node temperature array, the boundary node temperature array, the internal node pressure array, the boundary node pressure array, the internal node specific enthalpy array, the boundary node specific enthalpy array, the internal node pipe length array, the internal node diameter array, the internal node density array, and the boundary node density array; 5 groups of matrix data, namely the internal flow matrix, the boundary flow matrix, the internal resistance matrix, the boundary resistance matrix, and the fluid network topology matrix; and 1 numerical data, namely the inlet pressure value.

[0018] Furthermore, in step S1, the pipe network to be calculated is modeled according to the fluid network theory to obtain the fluid network topology matrix; the specific process is: a section of the pipe is regarded as an internal node, and the position where the pipe system boundary is connected to the outside of the system is set as the boundary node. The boundary node has temperature and pressure data, but no entity, so there is no pipe length and diameter data. The nodes are connected by streamlines, and the streamlines represent the fluid flow relationship between the pipes, thereby obtaining the fluid network topology matrix. The fluid network matrix includes the internal topology matrix and the boundary topology matrix, which are combined and called the fluid network topology matrix in actual use; the size of the internal topology matrix is n×n, where n is the number of internal nodes; the size of the boundary topology matrix is n×m, where n is the number of internal nodes and m is the number of boundary nodes; the internal node topology relationship matrix There are three values of : 0 means that there is no streamline connection between node i and node j; -1 means that the streamline direction is from i to j; 1 means that the streamline direction is from j to i; the array constructed in step S1, the array size associated with the internal nodes is n, and the array size associated with the boundary nodes is m; the matrix constructed in step S1, the matrix size associated with the internal is n×n, and the matrix size associated with the boundary is n×m.

[0019] Furthermore, in step S2, the five sets of data obtained in step S1, namely, the internal node pressure array, the boundary node pressure array, the fluid network topology matrix, the internal flow matrix and the boundary flow matrix, are solved simultaneously according to the mass conservation formula and the momentum conservation formula to construct a pressure matrix equation, and the pressure matrix is solved by the LU decomposition method to obtain an updated internal node pressure array. The specific process is as follows:

[0020] The mass conservation formula is:

[0021] ,

[0022] Where V is the node volume, is the node density, t is the time, Internal node topology relationship matrix, is the boundary topological relationship matrix, is the internal traffic matrix, is the boundary traffic matrix, n is the number of internal nodes, m is the number of external nodes, i, j, k are all node numbers, subscript ij represents the relationship between internal node i and internal node j, and subscript ik represents the relationship between internal node i and boundary node k;

[0023] The formula for conservation of momentum is:

[0024] ,

[0025] Where I is the structural parameter, is the internal traffic matrix, is the internal topological matrix, P represents the node pressure, H is the power source term, and f is the streamline resistance term. When calculating, the flow process is assumed to be stable, and the flow rate will not fluctuate, that is, the flow process is steady, then I is 0, and the mass conservation formula and momentum conservation formula are jointly expanded to obtain the pressure matrix equation:

[0026] ,

[0027] Among them, R represents the Darcy drag coefficient of the internal node, RE represents the Darcy drag coefficient of the boundary node, G is the internal flow matrix, GE is the boundary flow matrix, P is the internal node pressure, PE is the boundary node pressure, and t+1 is the next iteration time of t.

[0028] Furthermore, in step S3, the internal node pressure array obtained in step S2, and the four sets of data, namely, the internal resistance matrix, the boundary resistance matrix, and the fluid network topology matrix in step S1, are substituted into the streamline momentum equation for solving, thereby obtaining a new internal flow matrix;

[0029] In step S4, the internal flow matrix obtained in step S3 is combined with the internal node length array, internal node diameter array, internal node density array and boundary flow matrix obtained in step S1, and is substituted into the mass conservation formula to solve, thereby obtaining an updated internal node density array.

[0030] Furthermore, in step S5, the internal node density array obtained in step S4, the internal node pipe length array, the internal node pipe diameter array, the internal flow matrix, and the boundary flow matrix obtained in step S1 are substituted into the energy conservation formula, and the energy conservation formula is:

[0031] ,

[0032] Where V is the node volume, is the node density, is the internal topology matrix, is the boundary topology matrix, is the internal traffic matrix, is the boundary flow matrix, h is the internal node specific enthalpy, is the boundary node specific enthalpy, and S is the source term.

[0033] Furthermore, the step S7 is specifically as follows:

[0034] Determine the flow direction of the nodes based on the fluid network topology matrix in step S1. Take the inlet pressure value in step S1 as the starting point of the pipeline network. Substitute the internal flow matrix obtained in step S6, the internal resistance matrix and the boundary resistance matrix in step S1 into the Darcy-Weisbach formula to solve for the pressure difference between the nodes. Then, apply Kirchhoff's law. Starting from the starting point of the fluid network, update the pressure values of the nodes one by one according to the flow direction of the streamline between the nodes, and finally obtain a new internal node pressure array and a boundary node pressure array;

[0035] The Darcy - Weisbach formula is:

[0036] ,

[0037] where, is the head loss along the way, f is the friction coefficient, L is the pipeline length, D is the pipeline diameter, v is the average flow velocity of the fluid, and g is the acceleration due to gravity.

[0038] Further, the specific content of step S8 is as follows:

[0039] According to the internal node pressure array and boundary node pressure array obtained in step S7, the internal node specific enthalpy array obtained in step S5, the internal node pipeline length array, internal node pipe diameter array, and fluid network topology matrix obtained in step S1, perform numerical calculations with the help of the IAPWS water vapor database, and use the fluid network topology matrix for structure construction to obtain a new internal node density array. At the same time, recalculate the node resistance coefficient according to the Darcy-Weisbach formula, and then obtain a new internal resistance matrix and boundary resistance matrix.

[0040] Further, the specific content of step S9 is as follows:

[0041] By calculating the absolute value array of the residuals between the initial internal node pressure array entering step S2 and the updated internal node pressure array in step S7, if each item of the residual array is less than the set value, the loop ends; otherwise, use the internal node pressure array and boundary node pressure array in step S7, the internal node specific enthalpy array obtained in step S5, the internal node density array, internal resistance matrix and boundary resistance matrix in step S8, the internal node temperature array, boundary node temperature array, internal node pipeline length array, internal node pipe diameter array, boundary node specific enthalpy array, fluid network topology matrix in step S1, and the inlet pressure value as the initial values, and return to step S2 to continue the calculation.

[0042] The beneficial effects of the present invention are:

[0043] Innovation in the theoretical basis of the present invention: This algorithm is based on the fluid network theory, breaking through the computational limitations of traditional algorithms and providing new ideas and methods for the fluid hydraulic data processing of complex pipeline systems.

[0044] Enhanced data adaptability of the present invention: This algorithm can still effectively simulate and predict the fluid hydraulic data of the pipeline system in the case of fewer measurement points, unknown internal resistance coefficients of the pipeline, unobtainable pipeline valve opening data and valve relationships, greatly expanding the applicable range of the algorithm.

[0045] Improved prediction ability of the present invention: In the face of the above-mentioned dilemmas of many data deficiencies and uncertainties, the present invention demonstrates excellent simulation and prediction abilities, significantly improving the accuracy and reliability of fluid hydraulic data prediction and providing strong support for relevant decisions. Brief Description of the Drawings

[0046] Figure 1 is the flowchart of the present invention,

[0047] Figure 2 is a schematic diagram showing that the pipeline in the example of the present invention is divided into four nodes with two boundary nodes.

[0048] Figure 3 is the basic topological structure diagram of the pipeline network in the embodiment of the present invention. Detailed Embodiment

[0049] The present invention will be further clarified below in conjunction with the drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0050] Combined with the attached Figure 1 It can be seen that the specific process of the present invention is as follows:

[0051] S1 Data Input and Initialization: Input the fluid network topology structure matrix and the original boundary data of the fluid network, which include node temperature data, boundary node flow rate or pressure data, internal node pipe length and diameter data, and inlet pressure. Perform initialization processing on the input data: According to the fluid network topology matrix, vectorize the data of the nodes to be solved and the overall data, and matrixize the streamline data. With the help of the IAPWS water vapor library, calculate and solve other initial data based on the initial pressure and temperature. Finally, obtain 10 groups of vector data, namely the internal node temperature array, boundary node temperature array, internal node pressure array, boundary node pressure array, internal node specific enthalpy array, boundary node specific enthalpy array, internal node pipe length array, internal node diameter array, internal node density array, boundary node density array; 5 groups of matrix data, namely the internal flow matrix, boundary flow matrix, internal resistance matrix, boundary resistance matrix, fluid network topology matrix; and 1 numerical data, namely the inlet pressure value.

[0052] Model the pipe network to be calculated according to the fluid network theory. According to the pipe network installation drawing and calculation requirements, regard a section of pipe as an internal node, and set the positions where the pipe system boundary is connected to the outside of the system as boundary nodes. The boundary nodes have data such as temperature and pressure, but there is no entity, so there is no pipe length and diameter data. The nodes are connected by streamlines, and the streamlines represent the fluid flow relationship between the pipes, thus obtaining the fluid network topology matrix. The fluid network matrix includes the internal topology matrix and the boundary topology matrix, which are usually combined and called the fluid network topology matrix in actual use. The size of the internal topology matrix is n×n, where n is the number of internal nodes; the size of the boundary topology matrix is n×m, where n is the number of internal nodes and m is the number of boundary nodes. In the topology matrix, The value has three cases: 0 indicates that there is no streamline connection between node i and node j; -1 indicates that the streamline direction is from i to j; 1 indicates that the streamline direction is from j to i. The arrays constructed in S1, the arrays related to internal nodes have a size of n, and the arrays related to boundary nodes have a size of m; the matrices constructed in S1, the matrices related to the internal have a size of n×n, and the matrices related to the boundary have a size of n×m.

[0053] As Figure 2 shown, the pipe is divided into four nodes and there are two boundary nodes.

[0054] The internal topology matrix is ,

[0055] The boundary topology matrix is .

[0056] S2 sets the iteration step and solves the pressure matrix: After setting the iteration step, enter the iteration loop, and solve the five sets of data obtained in S1, namely the internal node pressure array, boundary node pressure array, fluid network topology matrix, internal flow matrix and boundary flow matrix, according to the mass conservation formula and momentum conservation formula, to construct the pressure matrix equation, and use the LU decomposition method to solve the pressure matrix, so as to obtain the updated internal node pressure array.

[0057] The mass conservation formula is:

[0058] ,

[0059] Where V is the node volume, is the node density, t is the time, is the internal node topological relationship matrix, is the boundary topological relationship matrix, is the internal traffic matrix, is the boundary flow matrix, n is the number of internal nodes, and m is the number of external nodes;

[0060] The formula for conservation of momentum is:

[0061] ,

[0062] Where I is the structural parameter, is the internal traffic matrix, is the internal topological matrix, P represents the node pressure, H is the power source term, and f is the streamline resistance term. When calculating, the flow process is assumed to be stable, and the flow rate will not fluctuate, that is, the flow process is steady, then I is 0, and the mass conservation formula and momentum conservation formula are jointly expanded to obtain the pressure matrix equation:

[0063] ,

[0064] Among them, R represents the Darcy drag coefficient of the internal node, RE represents the Darcy drag coefficient of the boundary node, G is the internal flow matrix, GE is the boundary flow matrix, P is the internal node pressure, PE is the boundary node pressure, and t+1 is the next iteration time of t.

[0065] S3 solves the new internal flow matrix: Substitute the internal node pressure array obtained in S2 and the four sets of data, namely the internal resistance matrix, boundary resistance matrix and fluid network topology matrix in S1, into the streamline momentum equation for solution to obtain a new internal flow matrix.

[0066] S4 Update the internal node density array: According to the internal flow matrix obtained in S3, combine the internal node pipe length array, internal node pipe diameter array, internal node density array, and boundary flow matrix obtained in S1, substitute them into the mass conservation formula for solution, and then obtain the updated internal node density array.

[0067] S5 Solve the updated internal node specific enthalpy array: Substitute the internal node density array obtained in S4, the internal node pipe length array, internal node pipe diameter array, internal flow matrix, and boundary flow matrix obtained in S1 into the energy conservation formula to construct a specific enthalpy matrix equation, and then use the LU decomposition method to solve the specific enthalpy matrix equation to obtain the updated internal node specific enthalpy array.

[0068] The energy conservation formula is:

[0069] ,

[0070] where V is the node volume, is the node density, is the internal node topological relationship matrix, is the boundary topological relationship matrix, is the internal flow matrix, is the boundary flow matrix, h is the internal node specific enthalpy, is the boundary node specific enthalpy, and S is the source term.

[0071] S6 Adjust the internal flow matrix: Add the internal flow matrix obtained after iteration in S3 to the initial internal flow matrix in S1 and take the average to obtain a new internal flow matrix. This step aims to slow down the convergence speed and prevent data distortion caused by too fast convergence.

[0072] S7 Update the node pressure array: Determine the flow direction of the nodes according to the fluid network topology matrix in S1. Take the inlet pressure value in S1 as the starting point of the pipeline network. Substitute the internal flow matrix obtained in S6, the internal resistance matrix and boundary resistance matrix in S1 into the Darcy - Weisbach formula to solve the pressure difference between the nodes. Then use Kirchhoff's law. Starting from the starting point of the fluid network, update the pressure values of the nodes one by one according to the flow direction of the streamline between the nodes, and finally obtain the new internal node pressure array and boundary node pressure array. Kirchhoff's law means that at the nodes of the fluid network, it is understood that the sum of the fluid flow rates flowing into the node is equal to the sum of the fluid flow rates flowing out of the node.

[0073] The Darcy - Weisbach formula is:

[0074] ,

[0075] where, is the head loss along the pipe, f is the friction coefficient, L is the pipe length, D is the pipe diameter, v is the average flow velocity of the fluid, and g is the acceleration due to gravity.

[0076] S8 Update the density array and the resistance matrix: Based on the internal node pressure array and the boundary node pressure array obtained in S7, the internal node specific enthalpy array obtained in S5, the internal node pipe length array, the internal node pipe diameter array, and the fluid network topology matrix obtained in S1, perform numerical calculations with the help of the IAPWS water vapor database, and use the fluid network topology matrix for structure construction to obtain a new internal node density array. At the same time, recalculate the node resistance coefficient according to the Darcy - Weisbach formula, and then obtain a new internal resistance matrix and a boundary resistance matrix.

[0077] S9 Determine whether the iteration ends: By calculating the absolute value array of the residuals between the initial internal node pressure array entering S2 and the updated internal node pressure array in S7, if each item in the residual array is less than the set value, end the loop; otherwise, use the internal node pressure array, the boundary node pressure array in S7, the internal node specific enthalpy array obtained in S5, the internal node density array, the internal resistance matrix, and the boundary resistance matrix in S8, the internal node temperature array, the boundary node temperature array, the internal node pipe length array, the internal node pipe diameter array, the boundary node specific enthalpy array, the fluid network topology matrix in S1, and the inlet pressure value as the initial values, and return to S2 to continue the calculation.

[0078] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention completely and clearly in conjunction with the logic diagram of the present invention:

[0079] Model the pipe network system to be calculated to obtain a fluid network relationship topology matrix, input this matrix and other physical quantities (temperature, flow matrix, and inlet pressure) into the algorithm program for initialization, and return the pressure distribution matrix after iterative operations.

[0080] This algorithm has higher accuracy and stability when dealing with problems such as few measurement points and missing data, and can provide more effective support for the design, operation, and maintenance of pipeline systems.

[0081] Figure 3 is the basic topological structure diagram of the pipeline network, Figure 3 The numbers in are the point numbers, that is, the measurement points, and there are no measurement points in the middle of the pipeline network. The following table shows the comparison between the simulated values and the measured values of each measurement point at three sets of times:

[0082] Table 1

[0083]

[0084] As can be seen from the deviation data in the above table, when the present invention is specifically applied, the deviation is within the allowable range, and it has industrial application value.

[0085] Taking the above ideal embodiments of the present invention as an inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for obtaining single-phase fluid hydraulic data of a pipe network system lacking measurement points, characterized in that, The following steps are involved: Step S1, data input and initialization: input the fluid network topology matrix and the original boundary data of the fluid network, and initialize the input data; Step S2, setting the iteration step size and solving the pressure matrix: after setting the iteration step size, entering the iteration loop, solving the data obtained in step S1 according to the mass conservation formula and the momentum conservation formula, constructing the pressure matrix equation, and solving the pressure matrix using the LU decomposition method; Step S3, solving a new internal flow matrix: Substituting the solution data of the pressure matrix obtained in step S2 and the data of step S1 into the streamline momentum equation for solving, and obtaining a new internal flow matrix; Step S4, updating the internal node density array: according to the internal flow matrix obtained in step S3, combined with the data in step S1, substitute into the mass conservation formula to solve, and then obtain the updated internal node density array; Step S5, solving the updated internal node specific enthalpy array: Substitute the internal node density array obtained in step S4 and the data obtained in step S1 into the energy conservation formula, construct the specific enthalpy matrix equation, and then use the LU decomposition method to solve the specific enthalpy matrix equation to obtain the updated internal node specific enthalpy array; Step S6, adjusting the internal flow matrix: adding the internal flow matrix obtained after iteration in step S3 to the initial internal flow matrix in step S1 and calculating the average value to obtain a new internal flow matrix; Step S7, updating the node pressure array: updating the pressure item by item according to Kirchhoff's law and Darcy-Weisbach formula; Step S8, updating the density array and the resistance matrix: updating to obtain a new internal resistance matrix and a boundary resistance matrix; Step S9, determine whether the iteration is finished: determine whether the pressure converges, if it converges, it is finished, if not, return to step S2.

2. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measuring points according to claim 1, characterized in that In step S1, the original boundary data of the fluid network includes node temperature data, boundary node flow or pressure data, internal node pipe length and diameter data, and inlet pressure; The specific steps for initializing the input data are as follows: based on the fluid network topology matrix, the node data to be determined and the overall data are vectorized, and the streamline data is matrixed; with the help of the IAPWS water vapor library, other initial data are calculated and solved through the initial pressure and temperature; finally, 10 sets of vector data are obtained, namely, the internal node temperature array, the boundary node temperature array, the internal node pressure array, the boundary node pressure array, the internal node specific enthalpy array, the boundary node specific enthalpy array, the internal node pipe length array, the internal node pipe diameter array, the internal node density array, and the boundary node density array; 5 sets of matrix data, namely, the internal flow matrix, the boundary flow matrix, the internal resistance matrix, the boundary resistance matrix, and the fluid network topology matrix; and 1 numerical data, namely, the inlet pressure value.

3. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measurement points according to claim 2, wherein, In the step S1, a fluid network model of the pipeline network to be calculated is established according to the fluid network theory to obtain a fluid network topology matrix. The specific process is as follows: A section of pipeline is regarded as an internal node, and the positions where the pipeline system boundary is connected to the outside of the system are set as boundary nodes. The boundary nodes have temperature and pressure data but no entity, so there is no pipe length and pipe diameter data. The nodes are connected by streamlines, and the streamlines represent the fluid flow relationship between the pipelines. Thus, a fluid network topology matrix is obtained. The fluid network matrix includes an internal topology matrix and a boundary topology matrix, which are combined and called the fluid network topology matrix in actual use. The size of the internal topology matrix is n×n, where n is the number of internal nodes; the size of the boundary topology matrix is n×m, where m is the number of boundary nodes. In the fluid network topology matrix, the values of the internal node topology relationship matrix D ij have three cases: 0 indicates that there is no streamline connection between node i and node j; -1 indicates that the streamline direction is from i to j; 1 indicates that the streamline direction is from j to i. The arrays constructed in step S1 have a size of n for the arrays related to internal nodes and a size of m for the arrays related to boundary nodes. The matrices constructed in step S1 have a size of n×n for the matrices related to the internal part and a size of n×m for the matrices related to the boundary part.

4. The method for obtaining single-phase fluid hydraulic data of a pipe network system lacking measurement points according to claim 1, characterized in that, In step S2, the five groups of data, namely the internal node pressure array, boundary node pressure array, fluid network topology matrix, internal flow matrix, and boundary flow matrix obtained in step S1, are simultaneously solved according to the mass conservation formula and the momentum conservation formula to construct a pressure matrix equation. The LU decomposition method is used to solve the pressure matrix, thereby obtaining the updated internal node pressure array. The specific process is as follows: The mass conservation formula is: Wherein, V is the node volume, ρ is the node density, t is the time, D ij is the internal node topology relation matrix, DE ik is the boundary topology relation matrix, G ij is the internal flow matrix, GE ik is the boundary flow matrix, n is the number of internal nodes, m is the number of external nodes, i, j, and k are all node numbers, the subscript ij represents the relationship between internal node i and internal node j, and the subscript ik represents the relationship between internal node i and boundary node k; the momentum conservation formula is: Among them, I is the structural parameter, G ij is the internal traffic matrix, D ij is the internal topological matrix, P represents the node pressure, H is the power source term, and f is the streamline resistance term. When calculating, the flow process is assumed to be stable, and the flow rate will not fluctuate, that is, the flow process is steady, then I is 0, and the mass conservation formula and momentum conservation formula are jointly expanded to obtain the pressure matrix equation: where R represents the Darcy resistance coefficient of internal nodes, RE represents the Darcy resistance coefficient of boundary nodes, G is the internal flow matrix, P is the internal node pressure, PE is the boundary node pressure, and t + 1 is the next iteration time of t.

5. The method for obtaining single-phase fluid hydraulic data of a pipe network system lacking measurement points according to claim 3, characterized in that, In step S3, the internal node pressure array obtained in step S2, along with the four groups of data, namely the internal resistance matrix, boundary resistance matrix, and fluid network topology matrix in step S1, are substituted into the streamline momentum equation for solution to obtain a new internal flow matrix; In step S4, according to the internal flow matrix obtained in step S3, combined with the internal node pipe length array, internal node pipe diameter array, internal node density array, and boundary flow matrix obtained in step S1, they are substituted into the mass conservation formula for solution, thereby obtaining the updated internal node density array.

6. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measuring points according to claim 3, characterized in that, In step S5, the internal node density array obtained in step S4, along with the internal node pipe length array, internal node pipe diameter array, internal flow matrix, and boundary flow matrix obtained in step S1, are substituted into the energy conservation formula. The energy conservation formula is: where V is the node volume, ρ is the node density, D ij is the internal topology matrix, DE ik is the boundary topology matrix, G ij is the internal flow matrix, GE ik is the boundary flow matrix, h is the specific enthalpy of the internal node, hE k is the specific enthalpy of the boundary node, S is the source term.

7. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measuring points according to claim 3, wherein The specific content of step S7 is as follows: Based on the fluid network topology matrix in step S1, determine the flow direction of the nodes. Take the inlet pressure value in step S1 as the starting point of the pipeline network. Substitute the internal flow matrix obtained in step S6, along with the internal resistance matrix and boundary resistance matrix in step S1, into the Darcy - Weisbach formula to solve for the pressure difference between the nodes. Then, using Kirchhoff's law, starting from the starting point of the fluid network, update the pressure values of the nodes one by one according to the flow direction of the streamline between the nodes. Finally, obtain the new internal node pressure array and boundary node pressure array. The Darcy - Weisbach formula is: where h f is the head loss along the path, f is the friction coefficient, L is the pipe length, D is the pipe diameter, v is the average flow velocity of the fluid, and g is the acceleration due to gravity.

8. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measurement points according to claim 3, characterized in that, The specific content of step S8 is as follows: According to the internal node pressure array and boundary node pressure array obtained in step S7, the internal node specific enthalpy array obtained in step S5, the internal node pipe length array, internal node pipe diameter array, and fluid network topology matrix obtained in step S1, perform numerical calculations with the help of the IAPWS water vapor database and use the fluid network topology matrix for structure construction to obtain a new internal node density array. At the same time, recalculate the node resistance coefficient according to the Darcy - Weisbach formula, thereby obtaining a new internal resistance matrix and boundary resistance matrix.

9. The method for obtaining the single-phase fluid hydraulic data of the pipe network system lacking measuring points according to claim 1, characterized in that, The specific content of step S9 is as follows: By calculating the absolute value array of residuals of the initial internal node pressure array entering step S2 and the updated internal node pressure array in step S7, if each item of the residual array is less than the set value, the loop ends; otherwise, the internal node pressure array, boundary node pressure array in step S7, the internal node specific enthalpy array obtained in step S5, the internal node density array, internal resistance matrix and boundary resistance matrix in step S8, the internal node temperature array, boundary node temperature array, internal node pipe length array, internal node pipe diameter array, boundary node specific enthalpy array, fluid network topology matrix in step S1, and the inlet pressure value are used as initial values, and the process returns to step S2 to continue the calculation.

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